Caniuse test page

About

This is a basic test suite of various web technologies for the When Can I Use website.

It is used to quickly test basic support for features in upcoming browsers, rather than any full support of the feature's specification.

Results on this page generally match the results as they appear on the When Can I Use site, but may not always due to a variety of circumstances (test may pass but support is actually buggy, not tested well enough, has alternative method, etc).

Four different types of tests are used:

Auto: Automated JS-based tests. (m) means Modernizr is used.
Visual: Requires visual confirmation/comparison to confirm
Visual-square: Test must create a 30x30px green (lime) square
Interactive: Requires interaction to confirm support

If you are interested in contributing tests, follow these instructions.

Select browser to compare results with:

Feature	Unprefixed tests	Prefixed tests
Resource Hints: dns-prefetch [Feat] [Tests]
Text API for Canvas [Feat] [Tests]	Auto(m) Modernizr test for: "canvastext"
WebGL - 3D Canvas graphics [Feat] [Tests]	Auto(m) Modernizr test for: "webgl" Visual-square getContext('experimental-webgl') Visual-square getContext('webgl')
Canvas blend modes [Feat] [Tests]	Visual-square Draw cyan and yellow rects on canvas with globalCompositeOperation to result in lime rectangle
WebGL 2.0 [Feat] [Tests]	Visual-square getContext('experimental-webgl2') Visual-square getContext('webgl2')
CSS image-set [Feat] [Tests]
CSS background-attachment [Feat] [Tests]	Auto background-attachment: fixed; property "sticks" Auto background-attachment: local; property "sticks" Interact Demo page Interact Mobile friendly test for "fixed"
CSS Anchor Positioning [Feat] [Tests]	Auto CSS.supports test for anchor-name: --foo
CSS Appearance [Feat] [Tests]	Auto appearance: none; property stays
CSS caret-color [Feat] [Tests]	Auto caret-color: blue; property "sticks" Interact Caret must be orange
CSS print-color-adjust [Feat] [Tests]	Auto color-adjust Test color-adjust: exact Auto print-color-adjust Test print-color-adjust: exact
CSS Container Queries (Size) [Feat] [Tests]	Auto
CSS Container Style Queries [Feat] [Tests]	Auto Test for CSS custom property: @container style(--works: true) Auto Test for regular CSS value: @container style(font-weight: bold)
CSS Containment [Feat] [Tests]	Auto strict CSS.supports test for contain: strict Auto content CSS.supports test for contain: content Auto size CSS.supports test for contain: size Auto layout CSS.supports test for contain: layout Auto paint CSS.supports test for contain: paint
CSS content-visibility [Feat] [Tests]	Auto CSS.supports test for content-visibility: hidden
CSS position:fixed [Feat] [Tests]	Auto Interact Test here
CSS font-palette [Feat] [Tests]	Auto CSS.supports test for font-palette: normal
CSS font-stretch [Feat] [Tests]	Auto font-stretch: condensed; property stays Visual Expanded Condensed Show expanded & condensed text
CSS hanging-punctuation [Feat] [Tests]	Auto CSS.supports test for hanging-punctuation: first Auto CSS.supports test for all hanging-punctuation variations Visual “foo bar quote mark should appear outside blue area Test for hanging-punctuation: first
CSS Initial Letter [Feat] [Tests]	Auto CSS.supports test for initial-letter: 3 Auto CSS.supports test for initial-letter-align: alphabetic Auto CSS.supports test for initial-letter-wrap: first
CSS initial value [Feat] [Tests]	Auto
letter-spacing CSS property [Feat] [Tests]	Auto AAAAAAAAAAA AAAAAAAAAAA AAAAAAAAAAA Test for fractional letter-spacing Visual-square AAAAAAAAAAAAA Test for negative letter spacing
CSS Motion Path [Feat] [Tests]	Auto motion-path: path("M900,190 L993,245;") Auto motion-offset: 50% Auto offset-path: path("M900,190 L993,245;") Auto offset-distance: 50%
CSS overflow property [Feat] [Tests]	Auto CSS.supports test for overflow-x: clip Visual-square Test for overflow: hidden visible; Visual-square Test for overflow-x: hidden; overflow-y: visible; Visual-square Test if overflow-x: clip works
CSS overscroll-behavior [Feat] [Tests]	Auto CSS.supports test for overscroll-behavior-y: contain Auto -ms-scroll-chaining: chained; property "sticks"
CSS page-break properties [Feat] [Tests]	Auto break-before: always; property "sticks" Auto page-break-before: always; property "sticks" Visual-square Test page-break-inside:avoid Visual-square Test column-break-inside:avoid Interact Test here
Rebeccapurple color [Feat] [Tests]	Auto Test if color is recognized Auto Test if color is rgb(102, 51, 153) Auto Color should be purple
CSS Scroll-behavior [Feat] [Tests]	Auto scroll-behavior: smooth; property "sticks" Auto Test if el.scrollBy({ "behavior": "smooth", "left": 0, "top": 0 }); does not throw an error
CSS Scroll Snap [Feat] [Tests]	Auto scroll-snap-type: inline mandatory; property "sticks" Auto scroll-snap-destination: 10px; property "sticks" Auto scroll-snap-coordinate: 10px; property "sticks" Auto scroll-snap-points-x: repeat(10px); property "sticks" Auto scroll-snap-points-x: snapList(10px); property "sticks" (older spec) Auto scroll-snap-margin: 5px; property "sticks" Auto scroll-snap-type: x proximity; property "sticks" Auto scroll-margin: 5px; property "sticks"
CSS position:sticky [Feat] [Tests]	Auto position: sticky; property stays Interact Test here
CSS Subgrid [Feat] [Tests]	Auto CSS.supports test for grid-template-rows: subgrid
CSS text-box-trim & text-box-edge [Feat] [Tests]	Auto a text-edge / leading-trim Auto a text-box-edge / text-box-trim
CSS text-justify [Feat] [Tests]	Auto CSS.supports test for text-justify: inter-word Auto Test if text-justify: distribute sticks Auto CSS.supports test for text-justify: inter-character
CSS text-orientation [Feat] [Tests]	Auto text-orientation: sideways property "sticks" Visual HOTEL Text should be vertical, but upright
CSS text-wrap: balance [Feat] [Tests]	Auto CSS.supports test for text-wrap: balance Auto text-wrap-style CSS.supports test for text-wrap-style: balance
CSS touch-action property [Feat] [Tests]	Auto touch-action: none; property stays
CSS @when / @else conditional rules [Feat] [Tests]	Auto @when Auto @else Auto inline @when
CSS widows & orphans [Feat] [Tests]	Auto orphans: 5; property "sticks" Auto widows: 5; property "sticks" Visual-square a a a a Test for orphans: 9 Visual-square a a a a Test for widows: 9
CSS font-size-adjust [Feat] [Tests]	Auto font-size-adjust: 1; property stays Visual-square x Test for font-size-adjust: 3
CSS font-variant-numeric [Feat] [Tests]	Auto Test all font-variant-numeric values
prefers-color-scheme media query [Feat] [Tests]	Auto prefers-dark-interface Auto Test all prefers-color-scheme variations
prefers-reduced-motion media query [Feat] [Tests]	Auto
CSS user-select: none [Feat] [Tests]	Auto user-select: none; property "sticks" Interact This text should be unselectable by the user. user-select: none;
CSS will-change property [Feat] [Tests]	Auto will-change: contents; property stays
:indeterminate CSS pseudo-class [Feat] [Tests]	Visual Visual Visual
::placeholder CSS pseudo-element [Feat] [Tests]	Visual Placeholder should be lime ::placeholder { color: lime; background-color: lime; opacity: 1 } (double colon) Visual Placeholder should be lime :placeholder { color: lime; background-color: lime; opacity: 1 } (single colon) Visual Placeholder should be lime ::input-placeholder { color: lime; background-color: lime; opacity: 1 } (double colon) Visual Placeholder should be lime :input-placeholder { color: lime; background-color: lime; opacity: 1 } (single colon)
:placeholder-shown CSS pseudo-class [Feat] [Tests]	Visual Placeholder should be lime :placeholder-shown { color: lime; background-color: lime; opacity: 1 } (single colon)
CSS :read-only and :read-write selectors [Feat] [Tests]	Visual div contenteditable disabled textarea readonly textarea textarea Test for :read-only & :read-write where appropriate Visual-square :read-write Visual-square :read-only
CSS scrollbar styling [Feat] [Tests]	Visual Should have green & lime scrollbar Visual Should have green & lime scrollbar
system-ui value for font-family [Feat] [Tests]	Visual Test: serif Test: system-ui Test: -apple-system
Variable fonts [Feat] [Tests]	Visual text - narrow text - wide Visual text - weight: 200 text - weight: 900 CFF2 format Visual text - weight: 200 text - weight: 900 CFF2 format (AdobeVFPrototype)
CSS Masks [Feat] [Tests]	Visual mask-image: url(alpha.png);
CSS all property [Feat] [Tests]	Visual-square Test for all:inherit
CSS :any-link selector [Feat] [Tests]	Visual-square
CSS background-blend-mode [Feat] [Tests]	Visual-square div with background image, background color & background-blend-mode: multiply
CSS Cascade Layers [Feat] [Tests]	Visual-square Test for @layer Interact Test here
Scoped Styles: the @scope rule [Feat] [Tests]	Visual-square
Case-insensitive CSS attribute selectors [Feat] [Tests]	Visual-square
CSS color() function [Feat] [Tests]	Visual-square display-p3 Test color(display-p3 0 1 0); Visual-square srgb Test color(srgb 0 1 0); Visual-square prophoto-rgb Test color(prophoto-rgb 0 1 0); Visual-square rec2020 Test color(rec2020 0 1 0); Visual-square xyz Test color(xyz 0 1 0);
CSS Container Query Units [Feat] [Tests]	Visual-square cqw Test for width:100cqw; height:100cqw; Visual-square cqh Test for width:100cqh; height:100cqh; Visual-square cqi Test for width:100cqi; height:100cqi; Visual-square cqb Test for width:100cqb; height:100cqb; Visual-square cqmin Test for width:100cqmin; height:100cqmin; Visual-square cqmax Test for width:100cqmax; height:100cqmax;
CSS Cross-Fade Function [Feat] [Tests]	Visual-square Test for cross-fade(url(green64x64.png), url(red30x30.png), 0%); Visual-square Test for cross-fade(url(red30x30.png), url(green64x64.png), 100%)
:dir() CSS pseudo-class [Feat] [Tests]	Visual-square
CSS display: contents [Feat] [Tests]	Visual-square
CSS Exclusions Level 1 [Feat] [Tests]	Visual-square Test for wrap-flow: both
CSS Grid Layout (level 1) [Feat] [Tests]	Visual-square Grid with two columns, two rows and three elements taking up space. Visual-square Grid with two columns, two rows and three elements taking up space.
:has() CSS relational pseudo-class [Feat] [Tests]	Visual-square
:in-range and :out-of-range CSS pseudo-classes [Feat] [Tests]	Visual-square Visual-square
LCH and Lab color values [Feat] [Tests]	Visual-square lch(87.74% 119.78 136.02) Visual-square lab(87.74% -86.18 83.18)
CSS line-clamp [Feat] [Tests]	Visual-square a a a a a a a a a a a a a a a a a a a a a a a a a a a NOTE: Forced -webkit- prefixes
:is() CSS pseudo-class [Feat] [Tests]	Visual-square :matches() Visual-square :any() Visual-square is()
CSS math functions min(), max() and clamp() [Feat] [Tests]	Visual-square min() Visual-square max() Visual-square clamp()
Blending of HTML/SVG elements [Feat] [Tests]	Visual-square Overlapping divs with mix-blend-mode: multiply
CSS namespaces [Feat] [Tests]	Visual-square Visual-square
CSS Nesting [Feat] [Tests]	Visual-square & Test for nested "&" Visual-square @nest Test for nested "@nest &"
selector list argument of :not() [Feat] [Tests]	Visual-square
selector list argument of :nth-child and :nth-last-child CSS pseudo-classes [Feat] [Tests]	Visual-square
CSS Relative color syntax [Feat] [Tests]	Visual-square Visual-square Visual-square hsl(from var(--color) calc(12deg * 10) s calc(100% / 2)) Visual-square currentcolor test hsl(from var(currentcolor) calc(12deg * 10) s calc(100% / 2))
CSS revert value [Feat] [Tests]	Visual-square
#rrggbbaa hex color notation [Feat] [Tests]	Visual-square #rgba Visual-square #rgba Visual-square #rrggbbaa Visual-square #rrggbbaa
CSS text-indent [Feat] [Tests]	Visual-square length text-indent: 30px; Visual-square each-line text-indent: 30px each-line; Visual-square hanging text-indent: 30px hanging;
CSS unset value [Feat] [Tests]	Visual-square Test for background:unset
CSS writing-mode property [Feat] [Tests]	Visual-square aaaaaaa
CSS zoom [Feat] [Tests]	Visual-square Test for zoom: 30
CSS currentColor value [Feat] [Tests]	Visual-square Test for background:currentColor; with parent having color set to "lime"
CSS justify-content: space-evenly [Feat] [Tests]	Visual-square flexbox Visual test for justify-content: space-evenly support in flexbox Visual-square grid justify-content: space-evenly in a grid
Small, Large, and Dynamic viewport units [Feat] [Tests]	Visual-square svh Test for width:100svh; height:100svh; Visual-square lvh Test for width:100lvh; height:100lvh; Visual-square dvh Test for width:100dvh; height:100dvh; Visual-square svw Test for width:100svw; height:100svw; Visual-square lvw Test for width:100lvw; height:100lvw; Visual-square dvw Test for width:100dvw; height:100dvw;
:default CSS pseudo-class [Feat] [Tests]	Interact Test here
CSS Device Adaptation [Feat] [Tests]	Interact Test page
::first-letter CSS pseudo-element selector [Feat] [Tests]	Interact test here
:focus-visible CSS pseudo-class [Feat] [Tests]	Interact Test here
CSS font-display [Feat] [Tests]	Interact Test here
::selection CSS pseudo-element [Feat] [Tests]	Interact This should be lime when selected ::selection { color: lime; background-color: lime }
ui-serif, ui-sans-serif, ui-monospace and ui-rounded values for font-family [Feat] [Tests]	Interact Test here
CSS Conical Gradients [Feat] [Tests]	Visual-square Test for conic-gradient(lime, lime, red); Visual-square Test for multiple stops
Media Queries: interaction media features [Feat] [Tests]	Visual-square Test support for @media (pointer:none), (pointer:coarse), (pointer:fine) Visual-square Test support for @media (any-hover:none), (any-hover:on-demand), (any-hover:hover) Visual-square Test support for @media (any-pointer:none), (any-pointer:coarse), (any-pointer:fine) Visual-square Test support for @media (hover:none), (hover:on-demand), (hover:hover)
Media Queries: Range Syntax [Feat] [Tests]	Visual-square Test support for @media (1px < width < 99999px)
gap property for Flexbox [Feat] [Tests]	Visual-square gap Test for gap: 30px; Visual-square row-gap Test for row-gap: 30px; Visual-square column-gap Test for column-gap: 30px;
:optional CSS pseudo-class [Feat] [Tests]	Visual-square Visual-square Test to ensure :optional does not apply to a required field
display: flow-root [Feat] [Tests]	Auto CSS.supports test for display: flow-root
display: run-in [Feat] [Tests]	Auto display: run-in; property "sticks" Interact W3 test 1, W3 test 2
CSS Table display [Feat] [Tests]	Visual topleft topright bottomleft bottomright Should be 2x2 table
CSS Counters [Feat] [Tests]	Visual-square Generated counter content should fill block with lime color.
CSS 2.1 selectors [Feat] [Tests]	Visual-square Test for child ( > )selector Visual-square Adjacent sibling selector test ( + ) Visual-square Attribute selector ( [role="none"] )
CSS min/max-width/height [Feat] [Tests]	Visual-square Visual-square Visual-square Visual-square
CSS inline-block [Feat] [Tests]	Visual-square
CSS3 selectors [Feat] [Tests]	Should be lime when box is checked Test for :checked support Interact Test here
text-emphasis styling [Feat] [Tests]	A B C D E F Should have blue triangles above text text-emphasis: filled triangle blue; Auto text-emphasis: circle filled; property "sticks" Auto text-emphasis-position: under left; property "sticks" Visual-square - Test for text-emphasis-style: filled circle; text-emphasis-position: over; text-emphasis-color: lime;
CSS3 Background-image options [Feat] [Tests]	Auto(m) Modernizr test for: "backgroundsize" Visual-square background-clip: content-box; Visual-square background-origin: content-box; Visual-square background-size: 30px 30px; Visual-square background-size: cover; Visual-square background: url(green5x5.png) no-repeat 0/cover; (shorthand)
CSS background-repeat round and space [Feat] [Tests]	Auto background-repeat: round; property "sticks" Interact Test here
CSS3 Border images [Feat] [Tests]	Auto(m) Modernizr test for: "borderimage" Visual Must include 2 or 3 full horizontal yellow diamonds Test for "round" - longhand Visual Must include full horizontal yellow diamonds w/spaces Test for "space" Visual-square Separate properties: border-image-source: url(green5x5.png); border-image-slice: 2; Visual-square Shorthand syntax: border-image: url(green5x5.png) 2;
CSS3 Border-radius (rounded corners) [Feat] [Tests]	Auto(m) Modernizr test for: "borderradius" Visual-square
CSS Animation [Feat] [Tests]	Auto(m) Modernizr test for: "cssanimations" Auto animation-timing-function: steps(4, end) property "sticks" Auto animation-timing-function: step-start property "sticks" Visual-square animation: staylime 60s infinite; @keyframes staylime { from { background-color: lime; } to { background-color: lime; } }
CSS3 Box-shadow [Feat] [Tests]	Auto(m) Modernizr test for: "boxshadow" Visual-square Test for support for basic support Visual-square Test for support for radius value Visual-square Test for support for multiple shadows Visual-square Test for support for "inset" shadow Visual-square Test for support for multiple inset shadows with radius
CSS Gradients [Feat] [Tests]	Auto(m) Modernizr test for: "cssgradients" Visual-square linear-gradient(to right, lime, lime, red); Visual-square radial-gradient(lime, lime) Visual-square linear-gradient(lime, lime)
CSS3 image-orientation [Feat] [Tests]	Auto image-orientation: from-image; property stays Visual-square Test image-orientation: from-image Visual-square Test image-orientation: 180deg Visual-square Test image-orientation: 180deg on image with no exif setting Visual-square Test image-orientation: flip on image with no exif setting
CSS Logical Properties [Feat] [Tests]	Auto Test for padding-inline-end: 10px Auto Test for margin-block: 0px Auto Test for inset-inline-start: 0px Auto Test for border-start-start-radius: 0px Visual-square Test for margin-start:30px Visual-square Test for margin-inline-start:30px Visual-square Test for text-align:end
CSS3 Opacity [Feat] [Tests]	Auto(m) Modernizr test for: "opacity" Visual-square Test for opacity: 0
CSS3 Text-shadow [Feat] [Tests]	Auto(m) Modernizr test for: "textshadow" Visual A font-size: 25px; color: white; text-shadow: 25px 0 3px lime; position: relative; left: -25px; Visual A Multiple shadow test Visual-square IIIII Multiple shadows with radius value
CSS3 Transitions [Feat] [Tests]	Auto(m) Modernizr test for: "csstransitions" Auto transition-timing-function: steps(4, end) property "sticks" Interact Green square must (briefly) appear on hover 5 second transition from left to right using cubic-bezier(0, 1, 1, 0);
CSS3 Colors [Feat] [Tests]	Auto(m) Modernizr test for: "hsla" Visual-square Visual-square
CSS Flexible Box Layout Module [Feat] [Tests]	Auto(m) Modernizr test for: "flexbox" Visual-square Test for display: box; (old syntax) Visual-square Test for display: flexbox; (2009 syntax) Visual-square Test for display: flex; (current syntax)
CSS3 font-kerning [Feat] [Tests]	Auto font-kerning: normal; property "sticks" Auto Test if text width changes when switching from font-kerning: none to font-kerning: normal on text 'AVAVAVAVAVAVAVAV'
Font unicode-range subsetting [Feat] [Tests]	Auto unicode-range: U+0400-14FF; property stays
CSS3 Multiple backgrounds [Feat] [Tests]	Auto(m) Modernizr test for: "multiplebgs" Visual-square background-repeat: repeat-x; background-image: url(green5x5.png), url(green5x5.png), url(green5x5.png), url(green5x5.png), url(green5x5.png), url(green5x5.png); background-position: 0 0, 0 5px, 0 10px, 0 15px, 0 20px, 0 25px;
CSS3 Multiple column layout [Feat] [Tests]	Auto(m) Modernizr test for: "csscolumns" Visual-square column-width: 15px; column-gap: 0; Visual-square column-width: 30px; column-gap: 0; break-after: column;
CSS3 2D Transforms [Feat] [Tests]	Auto(m) Modernizr test for: "csstransforms" Visual-square transform: translate(30px); Visual-square CSS transform on an SVG element
CSS3 3D Transforms [Feat] [Tests]	Auto(m) Modernizr test for: "csstransforms3d" Auto backface-visibility CSS.supports test for backface-visibility: visible Visual-square Parent: perspective: 100px; perspective-origin: 0% 50%; Child: transform: rotateY(-15deg);
@font-face Web fonts [Feat] [Tests]	Auto(m) Modernizr test for: "fontface"
CSS Counter Styles [Feat] [Tests]	Visual Should say "PASS" Interact Test here
Crisp edges/pixelated images [Feat] [Tests]	Visual img / bg / canvas Test for image-rendering: crisp-edges Visual img / bg / canvas - must be crisp Test for non-standard interpolation-mode: nearest-neighbor; Visual img / bg / canvas - must be crisp Test for image-rendering: optimize-contrast; (non-standard) Visual img / bg / canvas - must be crisp Test for image-rendering: pixelated;
CSS ::marker pseudo-element [Feat] [Tests]	Visual - should say "PASS" and be colored green
text-decoration styling [Feat] [Tests]	Visual Lime underline text-decoration-color: lime Visual Dashed underline text-decoration-style: dashed Visual Line-through text-decoration-line: line-through Visual Line-through/dashed/lime text-decoration-line: line-through dashed lime Visual Skip the s p a c e s text-decoration-skip: spaces
CSS3 Text-overflow [Feat] [Tests]	Visual abcdefghijklmnopqrstuvwxyz Should end with ellipsis text-overflow: ellipsis;
CSS Generated content for pseudo-elements [Feat] [Tests]	Visual - Element with CSS: #gencontent:before { content: 'A'; } #gencontent:after { content: 'Z'; }
CSS font-feature-settings [Feat] [Tests]	Visual LORE Combine L&O and R&E (current syntax) Current syntax: font-feature-settings: "dlig" 1; Visual LORE Combine L&O and R&E (old syntax) Old syntax: font-feature-settings: "dlig=1"; Visual-square tu If font-feature-settings:'ss06' 1; (or old syntax) works, the glyphs are replaced with larger ones.
calc() as CSS unit value [Feat] [Tests]	Visual-square width: calc(10px + 20px); Visual-square height: calc(60px - 100%); width: calc((100% / 2) + 15px - 0.5em); border-right: calc(0.5em) solid lime;
ch (character) unit [Feat] [Tests]	Visual-square A span with single character and font-size: 10ch;
CSS background-position edge offsets [Feat] [Tests]	Visual-square Test for background-position:bottom 0px right 0px;
CSS box-decoration-break [Feat] [Tests]	Visual-square abc def Test for box-decoration-break: clone
CSS element() function [Feat] [Tests]	Visual-square Test for background:element()
CSS Feature Queries [Feat] [Tests]	Visual-square Test for @supports ( display: block )
CSS filter() function [Feat] [Tests]	Visual-square
CSS Filter Effects [Feat] [Tests]	Visual-square filter: invert(1); Visual-square filter: url(css-filter.svg#invert);
CSS Hyphenation [Feat] [Tests]	Visual-square hyphenation Test for hyphens: none Visual-square hyphenation Test for hyphens: auto Visual-square hyphenation Test for hyphens: manual
CSS3 Media Queries [Feat] [Tests]	Visual-square Visual-square Test support for nested @media
CSS Regions [Feat] [Tests]	Visual-square Two elements: One content iframe with flow-into: flowname; and one div with flow-from: flowname; (IE10pp3) Visual-square Two elements: One with flow: "flowname"; and one with content: from-flow("flowname"); (Sept '11 WebKit nightlies) Visual-square Two elements: One with flow: "flowname"; and one with content: from-flow("flowname"); (Editor's Draft 30 September 2011)
CSS Shapes Level 1 [Feat] [Tests]	Visual-square Test to make element float box take up no space using polygon(0px 0px, 0px 0px) Interact Test suite Adobe test suite
CSS3 text-align-last [Feat] [Tests]	Visual-square Test for text-align-last: right Visual-square Test for text-align-last: right Visual-square Test for text-align-last: end Visual-square Test for text-align-last: end
CSS Variables (Custom Properties) [Feat] [Tests]	Visual-square on parent: --success-color: lime on child: background-color: var(--success-color);
CSS3 Box-sizing [Feat] [Tests]	Visual-square Visual-square Test for box-sizing: padding-box
CSS3 tab-size [Feat] [Tests]	Visual-square tab-size: 0; Visual-square tab-size: 60px;
CSS font-variant-alternates [Feat] [Tests]	Visual-square tu Test for font-variant-alternates: styleset(myset) Interact Test here
Intrinsic & Extrinsic Sizing [Feat] [Tests]	Visual-square min-content width: min-content Visual-square width: min-intrinsic Visual-square max-content width: max-content Visual-square fit-content() width: fit-content(30px) Interact Test here flex-basis flex-basis: max-content
CSS3 object-fit/object-position [Feat] [Tests]	Visual-square object-fit: contain Visual-square object-position: 30px 30px;
CSS outline properties [Feat] [Tests]	Visual-square Element with 0 width/height and 30px lime outline. Visual-square Test for outline-color: invert Visual-square outline-offset Test for outline-offset: 30px;
rem (root em) units [Feat] [Tests]	Visual-square A span with single character and font-size: 5rem;
Viewport units: vw, vh, vmin, vmax [Feat] [Tests]	Visual-square Test for width:100vmin; height:100vmin; Visual-square Test for width:100vh; height:100vh; Visual-square Test for width:100vw; height:100vw; Visual-square . Test for font-size: 100vw; Visual-square . Test for font-size: 100vh; Visual-square Test for width:100vmax; height:100vmax;
CSS3 word-break [Feat] [Tests]	Visual-square aaabbbcccdddeeefff Test for word-break: break-all; Visual-square 这是一些汉字 Test for word-break: keep-all;
CSS3 Overflow-wrap [Feat] [Tests]	Visual-square abcdefghijklmnop word-wrap: break-word; Visual-square abcdefghijklmnop overflow-wrap: break-word;
CSS resize property [Feat] [Tests]	Interact Must be able to resize element resize: both
CSS3 Cursors (original values) [Feat] [Tests]	Interact
CSS grab & grabbing cursors [Feat] [Tests]	Interact grab grabbing
CSS3 Cursors: zoom-in & zoom-out [Feat] [Tests]	Interact
CSS Repeating Gradients [Feat] [Tests]	Visual-square background: repeating-linear-gradient(0deg, lime, lime 30px, red 30px, red 60px);
CSS clip-path property (for HTML) [Feat] [Tests]	Visual-square Test for clip-path: polygon() Visual-square Test for clip-path: url('svg-clippath.svg#clipPolygon') Interact Test for clip-path: url(#foo) with inline SVG (button needed due to Chrome/Safari bug)
Media Queries: resolution feature [Feat] [Tests]	Visual-square Test for min-device-pixel-ratio Visual-square Test for min-resolution: 1dpi Visual-square Test for min-resolution: 0.01dppx Visual-square Test for min-resolution: 1dpcm Visual-square Test for min-resolution: 0.01x
CSS first-line pseudo-element [Feat] [Tests]	Auto foo bar first line should be lime (:first-line)
TTF/OTF - TrueType and OpenType font support [Feat] [Tests]	Visual Windsong font TTF font test Visual Windsong font OTF font test
EventTarget.addEventListener() [Feat] [Tests]	Auto Test for addEventListener without useCapture param Auto Test for addEventListener with useCapture param Auto click should turn it to lime Test for stopPropagation in event object
ChildNode.remove() [Feat] [Tests]	Auto Test for "remove" in document.body
Node.compareDocumentPosition() [Feat] [Tests]	Auto Test for 'compareDocumentPosition' in document.body Interact Test here
Window.devicePixelRatio [Feat] [Tests]	Auto
EventTarget.dispatchEvent [Feat] [Tests]	Auto
document.scrollingElement [Feat] [Tests]	Auto Test for 'scrollingElement' in document
document.head [Feat] [Tests]	Auto Test if document.head matches document.getElementsByTagName('head')[0]
DOM manipulation convenience methods [Feat] [Tests]	Auto
DOMContentLoaded [Feat] [Tests]	Auto Validates once DOMContentLoaded is triggered
DOMMatrix [Feat] [Tests]	Auto DOMMatrix Test for DOMMatrix in window Auto WebKitCSSMatrix Test for WebKitCSSMatrix in window Auto CSSMatrix Test for CSSMatrix in window Auto Methods Test if DOMMatrix methods exist Auto Test if DOMMatrix is used in SVG Auto Static methods Test if static DOMMatrix methods exist
Element.closest() [Feat] [Tests]	Auto Test Element.closest for self, parent and non-matching selector
document.elementFromPoint() [Feat] [Tests]	Auto Test for 'elementFromPoint' in document Auto Test if elementFromPoint matches expected element
getComputedStyle [Feat] [Tests]	Auto Test getComputedStyle to see if it correctly returns "display" property set on element. Auto Test getComputedStyle to see if it correctly returns "content" property set on element's :after pseudo-element.
HTMLElement.innerText [Feat] [Tests]	Auto Test if innerText got set as expected
autocomplete attribute: on & off values [Feat] [Tests]	Auto
Element.insertAdjacentElement() & Element.insertAdjacentText() [Feat] [Tests]	Auto insertAdjacentElement Test for 'insertAdjacentElement' in document.body Auto insertAdjacentText Test for 'insertAdjacentText' in document.body
"once" event listener option [Feat] [Tests]	Auto
Passive event listeners [Feat] [Tests]	Auto Test triggering a custom event with passive: true
querySelector/querySelectorAll [Feat] [Tests]	Auto Auto querySelector test on selector '[data-foo=bar] + ' Auto querySelectorAll test on selector '[data-foo=bar] + '
Shadow DOM (V1) [Feat] [Tests]	Auto el.attachShadow Test for 'attachShadow' in document.body Auto window.ShadowRoot Test for 'ShadowRoot' in window
Node.textContent [Feat] [Tests]	Auto Test if textContent got set as expected
Declarative Shadow DOM [Feat] [Tests]	Visual Test slotted content Visual Test shadowdom content Visual Test shadowdom content (shadowroot attribute) Visual Test slotted content (shadowroot attribute)
Client Hints: DPR, Width, Viewport-Width [Feat] [Tests]	Visual-square DPR Test if "DPR" header is returned Visual-square Width Test if "Width" header is returned Visual-square Viewport-Width Test if "Viewport-Width" header is returned
defer attribute for external scripts [Feat] [Tests]	Visual-square Test to see if defer script runs later.
focusin & focusout events [Feat] [Tests]	Interact Focus & unfocus field to test
inputmode attribute [Feat] [Tests]	Interact Must show numeric keypad
KeyboardEvent.code [Feat] [Tests]	Interact Type "a" Test if event.code for the "a" key returns "KeyA"
KeyboardEvent.getModifierState() [Feat] [Tests]	Interact Type "a" Test for e.getModifierState('Shift');
KeyboardEvent.key [Feat] [Tests]	Interact Type "a" Test if event.key for the "a" key returns "a" Interact Press arrow up Test if event.key for the arrow up key returns "ArrowUp"
KeyboardEvent.location [Feat] [Tests]	Interact Type "a" Test if event.location for the "a" key returns 0 Interact Type "a" Test if event.keyLocation for the "a" key returns 0 (older spec)
Resource Hints: modulepreload [Feat] [Tests]	Interact test here
Resource Hints: prefetch [Feat] [Tests]	Interact test here
Resource Hints: preload [Feat] [Tests]	Interact test here
Resource Hints: prerender [Feat] [Tests]	Interact test here
Media Fragments [Feat] [Tests]	Interact Should start on "3" Interact xywh=50,50,50,50
theme-color Meta Tag [Feat] [Tests]	Interact Test this page
Audio element [Feat] [Tests]	Auto document.createElement('audio').canPlayType Interact Audio element with 6 different sources (no MIME set) Interact Audio element with 6 different sources (with MIME set)
Audio Tracks [Feat] [Tests]	Auto Test for audioTracks in video
Autofocus attribute [Feat] [Tests]	Auto test here
Canvas (basic support) [Feat] [Tests]	Auto(m) Modernizr test for: "canvas" Visual-square Draw rect on canvas using fillStyle and fillRect
classList (DOMTokenList) [Feat] [Tests]	Auto "classList" in document.body Auto "classList" in document.body Auto "classList" in SVG element Visual-square Test for classList.add & classList.remove Visual-square Test for second toggle parameter Visual-square Test if multiple parameters for "add" are supported
Custom Elements (V1) [Feat] [Tests]	Auto window.customElements.define Test for customElements.define in window Auto Customized built-in element
dataset & data-* attributes [Feat] [Tests]	Auto Test for 'dataset' in document.body and getting the correct value returned from a data-foo attribute. Visual-square Test .dataset on SVG Interact Test here
Details & Summary elements [Feat] [Tests]	Auto Interact (summary button) (detail contents) "(detail contents)" should be visible ONLY after clicking summary Basic details element with summary and paragraph as children.
Dialog element [Feat] [Tests]	Auto Check for 'showModal' in document.createElement('dialog') Interact This is a dialog box Should open dialog box
disabled attribute of the fieldset element [Feat] [Tests]	Auto Interact Input field should be disabled
Attributes for form submission [Feat] [Tests]	Auto Test for form attribute properties Interact
Form validation [Feat] [Tests]	Auto Run checkValidity() on an email field with invalid email input Visual All fields should be lime Test for :valid, :invalid and :required CSS selectors Interact Form should show warning and NOT submit
getElementsByClassName [Feat] [Tests]	Auto Visual-square Test if two divs were correctly retrieved using getElementsByClassName Visual-square Test if SVG element was correctly retrieved using getElementsByClassName
hidden attribute [Feat] [Tests]	Auto Test for 'hidden' in document.body Visual-square Red square is hidden if attribute is supported
Session history management [Feat] [Tests]	Auto(m) Modernizr test for: "history" Auto Test if history.pushState was successful
HTML5 semantic elements [Feat] [Tests]	Auto Test if display value of main element is block Visual-square section, article, aside, hgroup, header, footer, nav tested for default "block" style.
sandbox attribute for iframes [Feat] [Tests]	Auto Test for "sandbox" property in iframe DOM object Visual-square Sandboxed iframe with page on other domain that would set its background to red if JS runs. Visual-square Sandboxed iframe allowing scripts (but not form submitting) with page on other domain that would set its background to red if a form WAS submitted. Visual-square Sandboxed iframe (no attribute value) with page on other domain that would set its background to red if a form WAS submitted.
srcdoc attribute for iframes [Feat] [Tests]	Auto Visual-square Test for iframe with srcdoc having lime background
naturalWidth & naturalHeight image properties [Feat] [Tests]	Auto
HTML Imports [Feat] [Tests]	Auto Test support for 'import' in document.createElement('link')
Email, telephone & URL input types [Feat] [Tests]	Auto Test if url type "sticks" for an input element Auto Test if tel type "sticks" for an input element Auto Test if email type "sticks" for an input element Interact Email: Tel: URL:
Multiple file selection [Feat] [Tests]	Auto Interact Must allow selection of more than 1 files
input placeholder attribute [Feat] [Tests]	Auto "placeholder" in document.createElement('input') Visual Placeholder text must say "PASS" Text input with placeholder value of "PASS"
Search input type [Feat] [Tests]	Auto Test if type as search is recognized Interact <- search <- text Search should appear differently
Lazy loading via attribute for images & iframes [Feat] [Tests]	Auto img Test for "loading" property in img element Auto iframe Test for "loading" property in iframe element
OffscreenCanvas [Feat] [Tests]	Auto Test for 'OffscreenCanvas' in window Auto Test for .getContext('2d') on an offscreen canvas Auto Test for .getContext('webgl') on an offscreen canvas
Reversed attribute of ordered lists [Feat] [Tests]	Auto Test for 'reversed' in ol element Visual Should number from 3 to 1
Ping attribute [Feat] [Tests]	Auto Interact Click here
readonly attribute of input and textarea elements [Feat] [Tests]	Auto Test for "readOnly" in input element Interact
Custom protocol handling [Feat] [Tests]	Auto Test for 'registerProtocolHandler' in navigator Interact Open caniusetest://mytest Link must open rph.html Interact Open web+caniusetest://mytest Link must open rph.html Test protocol "web+caniusetest"
relList (DOMTokenList) [Feat] [Tests]	Auto "relList" in document.createElement("a") Auto "relList" in document.createElement("link")
Ruby annotation [Feat] [Tests]	Auto display: ruby; property stays Auto display: ruby-base-container; property stays Auto ruby-position: over; property "sticks" Auto ruby-align: space-between; property "sticks" Visual (bottom1)(top1)(bottom2)(top2) Elements should be stacked on top of each other
Spellcheck attribute [Feat] [Tests]	Auto Check for 'spellcheck' in document.createElement('input') Auto Check for 'spellcheck' in document.createElement('textarea') Interact On: Off: Must have spellcheck only for first field
Srcset and sizes attributes [Feat] [Tests]	Auto Test for 'srcset' in document.createElement('img') Auto Test for 'sizes' in document.createElement('img') Auto Test if "sizes" works as expected
HTML templates [Feat] [Tests]	Auto Test for 'content' when creating a template element
Video element [Feat] [Tests]	Auto Auto Interact Video with controls and all three formats available. Interact Video with controls and all three formats available (with MIME).
Video Tracks [Feat] [Tests]	Auto Test for videoTracks in video
indeterminate checkbox [Feat] [Tests]	Visual Middle checkbox should appear different from checked & unchecked
meter element [Feat] [Tests]	Visual fail meter widget at 50%
progress element [Feat] [Tests]	Visual fail Progress widget at 50% Visual fail Indeterminate progress widget
Picture element [Feat] [Tests]	Visual-square Picture element with one source with min-width:0em media query that should override the src of the img element
async attribute for external scripts [Feat] [Tests]	Visual-square Test to see if async script runs later.
wbr (word break opportunity) element [Feat] [Tests]	Visual-square foofoofoofoofoofoo
contenteditable attribute (basic support) [Feat] [Tests]	Interact This element should be editable. Div element with attribute contenteditable="true"
Datalist element [Feat] [Tests]	Interact Show "foo" and "foobar" as options when "f" is entered
Download attribute [Feat] [Tests]	Interact Clicking link must download pass.txt, not navigate Link with download attribute pointing at a file.
Drag and Drop [Feat] [Tests]	Interact Test here Interact drag file here
Form attribute [Feat] [Tests]	Interact
HTML Media Capture [Feat] [Tests]	Interact Test here
Color input type [Feat] [Tests]	Interact Must provide widget to select color
Date and time input types [Feat] [Tests]	Interact Must provide widget to select date Interact Must provide widget to select time Interact Must provide widget to select date and time Interact Must provide widget to select month Interact Must provide widget to select week
input event [Feat] [Tests]	Interact Test input event on input type=text Interact Test input event on input type=checkbox
accept attribute for file input [Feat] [Tests]	Interact Must only accept audio files Interact sample png sample jpg Must only accept .png files Interact Must only accept image files
Number input type [Feat] [Tests]	Interact Must provide number widget Interact Must provide number widget with increments of 2 and max value of 6.
Range input type [Feat] [Tests]	Interact Must provide slider widget Interact Slider widget Uses -webkit-slider-thumb styling to make it visible/usable in Android browser
PNG favicons [Feat] [Tests]	Interact Test page
rel=noopener [Feat] [Tests]	Interact test here
tabindex global attribute [Feat] [Tests]	Interact Element focus should cycle from right to left
Path2D [Feat] [Tests]	Auto Test all Path2D methods
Minimum length attribute for input fields [Feat] [Tests]	Auto Test for 'minlength' in an input element Interact Form should show warning and NOT submit
Pattern attribute for input fields [Feat] [Tests]	Auto Test for "pattern" in input Visual All fields should be lime Test for :valid, :invalid with pattern attribute Interact Form should only submit if value is "pass"
Array.prototype.find [Feat] [Tests]	Auto Simple array.find() test
Array.prototype.findIndex [Feat] [Tests]	Auto
flat & flatMap array methods [Feat] [Tests]	Auto Test for Array.prototype.flat Auto Test for Array.prototype.flatMap Auto Test for Array.prototype.flat Auto Test for Array.prototype.flatMap
Array.prototype.includes [Feat] [Tests]	Auto
Async functions [Feat] [Tests]	Auto Test if async function can be created
BigInt [Feat] [Tests]	Auto Test for BigInt in window Auto Test for typeof 1n
const [Feat] [Tests]	Auto Test for const FOO = 'bar'; Auto Test if const is block scoped Auto Test if const is block scoped with "use strict" Auto Test for const FOO = 'bar'; with "use strict" Visual-square Test if const cannot be changed Visual-square Test if const cannot be changed (with "use strict")
Date.prototype.toLocaleDateString [Feat] [Tests]	Auto no param Auto en-US & en-GB locale tests Auto options Auto Other locales Auto options IANA timeZone & timeZoneName
Internationalization API [Feat] [Tests]	Auto Test for Intl.Collator Auto Test for Intl.DateTimeFormat Auto Test for Intl.NumberFormat
Lookbehind in JS regular expressions [Feat] [Tests]	Auto
localeCompare() [Feat] [Tests]	Auto Auto Test 'a'.localeCompare('b') === -1 Auto locale Test 'ä'.localeCompare('z', 'de') < 0 Auto locale Test 'ä'.localeCompare('z', 'sv') > 0 Auto options Test 'ä'.localeCompare('a', 'de', { sensitivity: 'base' }) Auto options Test 'ä'.localeCompare('a', 'sv', { sensitivity: 'base' }) > 0
Object.entries [Feat] [Tests]	Auto Auto
Object.values method [Feat] [Tests]	Auto
String.prototype.padStart(), String.prototype.padEnd() [Feat] [Tests]	Auto Test for padStart & padEnd in String.prototype Auto Small padStart & padEnd tests
Promise.prototype.finally [Feat] [Tests]	Auto Test if finally block is reached
Promises [Feat] [Tests]	Auto Create a promise and resolve with parameter Auto finally() Create a promise and test finally
Shared Array Buffer [Feat] [Tests]	Auto Test for SharedArrayBuffer without COOP/COEP enabled Test for 'SharedArrayBuffer' in window Interact Test here Test for SharedArrayBuffer with COOP/COEP enabled
JavaScript modules via script tag [Feat] [Tests]	Visual-square Test module in iframe Visual-square "nomodule" test Test nomodule in iframe
ECMAScript 5 [Feat] [Tests]	Interact test here
ECMAScript 2015 (ES6) [Feat] [Tests]	Interact Test here
JSON parsing [Feat] [Tests]	Auto Auto Create a JS object, convert to JSON string, convert back to object and compare.
ECMAScript 5 Strict Mode [Feat] [Tests]	Auto Test for error thrown using "use strict" and var a = {a:1,a:1}; Interact Test here External test suite
Arrow functions [Feat] [Tests]	Auto Test if var fn = (n => n + 1) properly increments by one
ES6 classes [Feat] [Tests]	Auto Auto strict mode
ES6 Generators [Feat] [Tests]	Auto
ES6 Number [Feat] [Tests]	Auto isFinite Auto isInteger Auto isSafeInteger Auto isNaN Auto EPSILON Auto MIN_SAFE_INTEGER Auto MAX_SAFE_INTEGER
String.prototype.includes [Feat] [Tests]	Auto Test for 'includes' in String.prototype Auto Test if .includes() works
let [Feat] [Tests]	Auto let foo = 'bar' Auto let foo = 'bar' with "use strict" Visual-square Test let support using the "application/javascript;version=1.7" type on the script tag
Proxy object [Feat] [Tests]	Auto Test for global Proxy object & revocable method
Rest parameters [Feat] [Tests]	Auto Test if rest parameter has correct amount of items
ES6 Template Literals (Template Strings) [Feat] [Tests]	Auto
Typed Arrays [Feat] [Tests]	Auto Check for Int8Array in window Auto Check for Uint8Array in window Auto Check for Uint8ClampedArray in window Auto Check for Int16Array in window Auto Check for Uint16Array in window Auto Check for Int32Array in window Auto Check for Uint32Array in window Auto Check for Float32Array in window Auto Check for Float64Array in window Auto Test for ArrayBuffer
JavaScript modules: dynamic import() [Feat] [Tests]	Visual-square Test import()
Intl.PluralRules API [Feat] [Tests]	Auto Test for 'PluralRules' in window.Intl Auto Test that new Intl.PluralRules('en-US').select(1) === 'one'
Accelerometer [Feat] [Tests]	Auto Test for 'Accelerometer' in window Auto Test constructor
Ambient Light Sensor [Feat] [Tests]	Auto Check for 'ondevicelight' in window Auto Check for 'onlightlevel' in window
Asynchronous Clipboard API [Feat] [Tests]	Auto Test for navigator.clipboard methods Interact Can request "clipboard-write" permission Interact First copy text from input field: Test readText() method
Base64 encoding and decoding [Feat] [Tests]	Auto Test if window.btoa and window.atob work
Web Audio API [Feat] [Tests]	Auto
Auxclick [Feat] [Tests]	Auto Test for onauxclick in window Interact turn lime on non-primary click
Battery Status API [Feat] [Tests]	Auto Test if "battery" in navigator is an object Auto Test if "getBattery" in navigator is a function
Beacon API [Feat] [Tests]	Auto Test for 'sendBeacon' in navigator Visual-square Test if sendBeacon works on beforeunload event
Printing Events [Feat] [Tests]	Auto onbeforeprint Auto onafterprint Test for "onafterprint" in window Interact Test here
BroadcastChannel [Feat] [Tests]	Auto "BroadcastChannel" in window
Synchronous Clipboard API [Feat] [Tests]	Auto Check for "onpaste" in document Auto Test for ClipboardEvent in window Auto ClipboardEvent constructor Interact Pasting text should turn background lime Test if document.onpaste is triggered and has clipboardData Interact Pasting text should turn background lime (IE) Test if window.onpaste is triggered and window.clipboardData has data (IE proprietary) Interact select this Paste here: copy button should copy to clipboard Interact Copy this text Copying text should turn background lime Test if document.oncopy is triggered and has clipboardData Interact paste button should fire paste event
Basic console logging functions [Feat] [Tests]	Auto Test for console.log(); Auto Test for console.error(); Auto Test for console.warn(); Auto Test for console.info();
Constraint Validation API [Feat] [Tests]	Auto Auto Auto Test validity properties
createImageBitmap [Feat] [Tests]	Auto Test for 'createImageBitmap' in window Auto resizeWidth&resizeHeight
CSS Painting API [Feat] [Tests]	Auto Test for 'paintWorklet' in window.CSS Visual-square
CSS.supports() API [Feat] [Tests]	Auto two arguments Test for CSS.supports("color", "lime"); Auto supportsCSS Test for supportsCSS("color", "lime"); Auto single argument condition Test for CSS.supports("color: lime");
CustomEvent [Feat] [Tests]	Auto Test for document.createEvent('CustomEvent') Auto Test if window.CustomEvent exists Auto Test for CustomEvent constructor
DeviceOrientation & DeviceMotion events [Feat] [Tests]	Auto Check for DeviceOrientationEvent in window Auto Must change to lime when device orientation changes. Add 'deviceorientation' event listener to window. Auto Check for 'oncompassneedscalibration' in window Auto Check for DeviceMotionEvent in window
document.currentScript [Feat] [Tests]	Auto Test for 'currentScript' in document Auto Test if document.currentScript is the last accessible script
Document Object Model Range [Feat] [Tests]	Auto Test for 'createRange' in document Auto foobar Various range tests Interact test getSelection() here
Scroll methods on elements (scroll, scrollTo, scrollBy) [Feat] [Tests]	Auto Test if 'scroll', 'scrollTo', 'scrollBy' exist in an element Visual-square scroll({behavior: 'smooth'}) Visual-square scrollBy with options Visual-square scrollTo(0, 100)
Server-sent events [Feat] [Tests]	Auto
Fetch [Feat] [Tests]	Auto Test for "fetch" in window
File API [Feat] [Tests]	Auto Auto "Blob" in window Auto "File" in window Auto Test for File constructor Interact Test here
CSS Font Loading [Feat] [Tests]	Auto Test if window.FontFace is a function
Fullscreen API [Feat] [Tests]	Auto Check for requestFullScreen in document.body (supports old draft) Auto Check for requestFullscreen in document.body (supports current draft) Interact Clicking button should send request to go into full screen mode Test requestFullscreen
Gamepad API [Feat] [Tests]	Auto Test for 'Gamepad' in window
Geolocation [Feat] [Tests]	Auto(m) Modernizr test for: "geolocation" Auto Test for getCurrentPosition, watchPosition and clearWatch in navigator.geolocation Interact Must provide LAT and LON info (may need to give permission first) Test for navigator.geolocation.getCurrentPosition on which position.coords.latitude and position.coords.longitude are expected.
crypto.getRandomValues() [Feat] [Tests]	Auto Test for window.crypto.getRandomValues()
Gyroscope [Feat] [Tests]	Auto Test for 'Gyroscope' in window Auto Test constructor
navigator.hardwareConcurrency [Feat] [Tests]	Auto Test for 'hardwareConcurrency' in navigator Visual Processors available:
Hashchange event [Feat] [Tests]	Auto(m) Modernizr test for: "hashchange" Visual-square iframe with addEventListener('hashchange', function() { document.body.style.background = 'lime'; }, false);
High Resolution Time API [Feat] [Tests]	Auto test if performance.now() returns a number
IndexedDB [Feat] [Tests]	Auto(m) Modernizr test for: "indexeddb" Auto Test for "indexedDB" in window Auto Test if onupgradeneeded or onsuccess fired Interact Test conformance here
IndexedDB 2.0 [Feat] [Tests]	Auto Test for 'onclose' in db & 'objectStoreNames' in transaction
Selection controls for input & textarea [Feat] [Tests]	Auto Test 'setSelectionRange' 'selectionStart', 'selectionEnd' in input Auto Test 'setSelectionRange' 'selectionStart', 'selectionEnd' in textarea Auto Test if setSelectionRange works and selectionStart & selectionEnd are correct
IntersectionObserver [Feat] [Tests]	Auto Test for 'IntersectionObserver' in window Auto Interact Test "isIntersecting" here
Magnetometer [Feat] [Tests]	Auto Test for 'Magnetometer' in window Auto Test constructor
matches() DOM method [Feat] [Tests]	Auto Test for "matchesSelector" in document.body Auto Test for "matches" in document.body
matchMedia [Feat] [Tests]	Auto Check for matchMedia in window
Media Source Extensions [Feat] [Tests]	Auto Auto Test for "sourceopen" event and check existence of 'sourceBuffers'
Web MIDI API [Feat] [Tests]	Auto Test for "getMIDIAccess" in navigator object
Mutation Observer [Feat] [Tests]	Auto "MutationObserver" in window Auto Test if MutationObserver works
Web Storage - name/value pairs [Feat] [Tests]	Auto(m) Modernizr test for: "localstorage" Auto Test if getItem, setItem and removeItem work.
Navigation Timing API [Feat] [Tests]	Auto Test for performance in window Auto Test for "timing" in window.performance Auto Test for all properties in performance.timing
Web Notifications [Feat] [Tests]	Auto Test for "notifications" in window (older spec) Auto Try creating "Notification", check for "show" function in notification instance. Auto Test for 'Notification' in window Interact Must show a notification Create notification
Object RTC (ORTC) API for WebRTC [Feat] [Tests]	Auto Auto
Online/offline status [Feat] [Tests]	Auto Test for 'onLine' in navigator Auto Should go lime when going from off to online Auto Should go lime when going from on to offline
Orientation Sensor [Feat] [Tests]	Auto Test for 'AbsoluteOrientationSensor' in window Auto Test constructor
PageTransitionEvent [Feat] [Tests]	Auto Auto Visual-square Test for iframe with page that turns lime on "pageshow" event
Page Visibility [Feat] [Tests]	Auto typeof document.hidden == "boolean" Auto typeof document.visibilityState == "string"
Payment Request API [Feat] [Tests]	Auto Test for 'PaymentRequest' in window Auto Test for PaymentResponse.prototype.retry
Picture-in-Picture [Feat] [Tests]	Auto Test for webkitSetPresentationMode Auto Interact
Pointer Lock API [Feat] [Tests]	Auto Test for requestPointerLock in document.body Auto test for movementX in new MouseEvent('mousemove') Interact Test here
Proximity API [Feat] [Tests]	Auto Check for 'ondeviceproximity' in window Auto Check for 'onuserproximity' in window
Push API [Feat] [Tests]	Auto Test for PushSubscription in window Auto Test for PushManager in window
requestAnimationFrame [Feat] [Tests]	Auto Test the requestAnimationFrame callback Auto Check for requestAnimationFrame in window Auto Check for cancelAnimationFrame in window
requestIdleCallback [Feat] [Tests]	Auto Auto Test if requestIdleCallback callback is called
Resize Observer [Feat] [Tests]	Auto Test for 'ResizeObserver' in window
Resource Timing (basic support) [Feat] [Tests]	Auto Test if window.performance.getEntriesByName is a function
WebRTC Peer-to-peer connections [Feat] [Tests]	Auto Test for "RTCPeerConnection" in window object
Screen Orientation [Feat] [Tests]	Auto Test if window.screen.orientation is a string Auto Test if window.screen.orientation is an object Interact Interact
Selection API [Feat] [Tests]	Auto Test for 'getSelection' in window Auto Test for 'onselectstart' in document Auto Test for 'onselectionchange' in document Visual Select this text selectstart triggered: no selectionchange triggered: no
Server Timing [Feat] [Tests]	Auto Test for 'PerformanceServerTiming' in window Visual-square Test server-timing values
Service Workers [Feat] [Tests]	Auto Test for 'serviceWorker' in navigator
getUserMedia/Stream API [Feat] [Tests]	Auto Test for "getUserMedia" in navigator object Auto Test for "srcObject" in video element Auto Test for navigator.mediaDevices.getUserMedia Interact Test here
Streams [Feat] [Tests]	Auto WritableStream Auto basic support Auto pipeTo / pipeThrough Auto BYOB
Temporal [Feat] [Tests]	Auto Test for Temporal in window
TextEncoder & TextDecoder [Feat] [Tests]	Auto Test for 'TextEncoder' in window Auto Test if TextEncoder returns expected result Auto Test for 'TextDecoder' in window Auto Test if TextDecoder returns expected result
Touch events [Feat] [Tests]	Auto(m) Modernizr test for: "touch"
unhandledrejection/rejectionhandled events [Feat] [Tests]	Auto Test for 'onunhandledrejection' in window Auto Test for 'onrejectionhandled' in window
URL API [Feat] [Tests]	Auto Auto Test all url properties Auto Test base parameter
URLSearchParams [Feat] [Tests]	Auto window.URLSearchParams Test for 'URLSearchParams' in window Auto .get() Test for new URLSearchParams() & params.get()
User Timing API [Feat] [Tests]	Auto Test performance.mark and performance.getEntriesByType('mark') Auto Test performance.measure and performance.getEntriesByType('measure')
Vibration API [Feat] [Tests]	Auto Test if "vibrate" in navigator is a function
View Transitions API (single-document) [Feat] [Tests]	Auto Auto
Screen Wake Lock API [Feat] [Tests]	Auto Test for 'wakeLock' in navigator
Web Animations API [Feat] [Tests]	Auto Test .animate(), should animate from red to lime Auto Test if player.pause is function Auto Test if getAnimations works on document Auto Test for document.timeline.currentTime Auto Test for various animation API constructors in window Auto Test if animation.ready is a promise Auto Test if various animation props & methods exist Auto Test if animation effect methods exist Auto Test if effect timing props exist Auto Test for animation.effect.composite
Web Share API [Feat] [Tests]	Auto Test for "share" in navigator
WebCodecs API [Feat] [Tests]	Auto AudioDecoder Auto VideoDecoder Auto AudioEncoder Auto VideoEncoder Auto Other interfaces
WebGPU [Feat] [Tests]	Auto Test for navigator.gpu Auto Test for GPUBufferUsage.COPY_SRC
Web Sockets [Feat] [Tests]	Auto(m) Modernizr test for: "websockets" Auto Test for binary websockets support
WebTransport [Feat] [Tests]	Auto Test for "WebTransport" in window
Web Workers [Feat] [Tests]	Auto(m) Modernizr test for: "webworkers" Auto Create a new Worker using new Worker('worker.js'); Then, test postMessage and onmessage event.
WebXR Device API [Feat] [Tests]	Auto xr.supportsSession Test for navigator.xr.supportsSession
Cross-document messaging [Feat] [Tests]	Auto(m) Modernizr test for: "postmessage"
XMLHttpRequest advanced features [Feat] [Tests]	Auto Auto Test for 'timeout' property Auto Test for xhr.responseType = 'json'
DOM Parsing and Serialization [Feat] [Tests]	Auto Test DOMParser.parseFromString Auto Test XMLSerializer.serializeToString Auto Test innerHTML get and set Auto Test outerHTML get and set Auto Test insertAdjacentHTML with beforebegin and beforeend
Element.insertAdjacentHTML() [Feat] [Tests]	Visual-square Interact more tests
scrollIntoView [Feat] [Tests]	Visual-square scrollIntoView() Visual-square scrollIntoView(false) Visual-square scrollIntoView({behavior: 'smooth'})
Element.getBoundingClientRect() [Feat] [Tests]	Interact Test here
Pointer events [Feat] [Tests]	Interact Must turn lime on click or tap Tests support for "pointerdown" event Interact Must turn lime on "pointerover" Tests support for "pointerover" event
console.time and console.timeEnd [Feat] [Tests]	Auto Test for console.time() & console.timeEnd();
AbortController & AbortSignal [Feat] [Tests]	Auto Test for AbortController & AbortSignal in window Auto Test creating new AbortController
Blob constructing [Feat] [Tests]	Auto "BlobBuilder" in window Auto new Blob(["hey!<\/b><\/a>"], { "type" : "text\/xml" });
Blob URLs [Feat] [Tests]	Auto Select a file to test support Test for window.URL.createObjectURL by selecting file.
FileReader API [Feat] [Tests]	Auto Check for FileReader in window
FileReaderSync [Feat] [Tests]	Auto Test filereadersync in a worker Auto Test if filereadersync exists in a worker
maxlength attribute for input and textarea elements [Feat] [Tests]	Auto Test for maxLength property Interact Should only allow one character to be entered Interact abc Change text length to 1+ chars, then click Test for el.validity.tooLong
ImageCapture API [Feat] [Tests]	Auto Auto
Media Capture from DOM Elements API [Feat] [Tests]	Auto video Test for 'captureStream' in document.createElement('video') Auto audio Test for 'captureStream' in document.createElement('audio') Auto canvas Test for 'captureStream' in document.createElement('canvas')
MediaRecorder API [Feat] [Tests]	Auto Test for 'MediaRecorder' in window Interact Test demo here
Shared Web Workers [Feat] [Tests]	Auto Create a new SharedWorker using new SharedWorker('sharedworker.js'); Then, test worker.port.onmessage event.
Channel messaging [Feat] [Tests]	Auto "MessageChannel" in window Auto "MessagePort" in window
Dynamic Adaptive Streaming over HTTP (MPEG-DASH) [Feat] [Tests]	Auto video.canPlayType('application/dash+xml')
WebAssembly [Feat] [Tests]	Auto window.Wasm & Wasm.instantiateModule Auto window.WebAssembly & WebAssembly.compile
XHTML served as application/xhtml+xml [Feat] [Tests]	Auto
HEIF/HEIC image format [Feat] [Tests]	Visual HEIF image
MathML [Feat] [Tests]	Visual
AVIF image format [Feat] [Tests]	Visual-square 30x30 lime avif image Visual-square must animate animated avif image Visual-square lossy lossy lime avif image Visual-square lossless lossless lime avif image
Data URIs [Feat] [Tests]	Visual-square div with data URL as background image
JPEG 2000 image format [Feat] [Tests]	Visual-square 30x30 lime jpeg2000 image
JPEG XL image format [Feat] [Tests]	Visual-square lime jpegxl image
JPEG XR image format [Feat] [Tests]	Visual-square 30x30 lime jpegxr image Visual-square 30x30 lime lossless jpegxr image
SDCH Accept-Encoding/Content-Encoding [Feat] [Tests]	Visual-square
WebP image format [Feat] [Tests]	Visual-square 5x5 lime webp image sized at 30x30
asm.js [Feat] [Tests]	Interact Test here (result should be significant difference)
Brotli Accept-Encoding/Content-Encoding [Feat] [Tests]	Interact test here content-encoding: brotli Interact test here content-encoding: br
CSS Paged Media (@page) [Feat] [Tests]	Interact Test here
HTTP/2 protocol [Feat] [Tests]	Interact browser test for HTTP2
HTTP/3 protocol [Feat] [Tests]	Interact Cloudflare test Fastly test nginx test
Built-in PDF viewer [Feat] [Tests]	Interact Test this PDF file
WAI-ARIA Accessibility features [Feat] [Tests]	Interact
zstd (Zstandard) content-encoding [Feat] [Tests]	Interact Test here
FLAC audio format [Feat] [Tests]	Auto canPlayType('audio/flac') Interact Audio element with flac file
AAC audio file format [Feat] [Tests]	Interact Audio element with aac file
MP3 audio format [Feat] [Tests]	Interact Audio element with mp3 file
Ogg Vorbis audio format [Feat] [Tests]	Interact Audio element with ogg vorbis file
Opus audio format [Feat] [Tests]	Interact Audio element with opus file
Wav audio format [Feat] [Tests]	Interact Audio element with wav file
WOFF - Web Open Font Format [Feat] [Tests]	Visual Windsong font
WOFF 2.0 - Web Open Font Format [Feat] [Tests]	Visual Windsong font
COLR/CPAL(v0) Font Formats [Feat] [Tests]	Interact Test here
COLR/CPAL(v1) Font Formats [Feat] [Tests]	Interact Test here Emoji on left should be vector versions of emoji on right
MPEG-4/H.264 video format [Feat] [Tests]	Auto Interact Video with source element and MIME set Interact Video with source element Interact Video, no MIME, no type attribute.
Ogg/Theora video format [Feat] [Tests]	Auto Interact Video with source element and MIME set Interact Video with source element Interact Video, no MIME, no type attribute.
WebM video format [Feat] [Tests]	Auto Interact Video with source element and MIME set Interact Video with source element Interact Video, no MIME, no type attribute.
AV1 video format [Feat] [Tests]	Interact Demo 1 Demo 2 Interact mkv Interact opus mp4 Interact aac mp4
HEVC/H.265 video format [Feat] [Tests]	Interact
WebVTT - Web Video Text Tracks [Feat] [Tests]	Interact Must say "WebVTT Success!" if supported Video with controls and WebVTT file
WebAssembly BigInt to i64 conversion in JS API [Feat] [Tests]	Auto
WebAssembly Bulk Memory Operations [Feat] [Tests]	Auto
WebAssembly Multi-Value [Feat] [Tests]	Auto
WebAssembly Import/Export of Mutable Globals [Feat] [Tests]	Auto
WebAssembly Non-trapping float-to-int Conversion [Feat] [Tests]	Auto
WebAssembly Reference Types [Feat] [Tests]	Auto
WebAssembly Sign Extension Operators [Feat] [Tests]	Auto
WebAssembly SIMD [Feat] [Tests]	Auto
WebAssembly Threads and Atomics [Feat] [Tests]	Interact Test here
Animated PNG (APNG) [Feat] [Tests]	Auto Test for second frame using Canvas element Visual Must animate
PNG alpha transparency [Feat] [Tests]	Visual
Cross-Origin Resource Sharing [Feat] [Tests]	Auto Instant XHR request on page that should permit it.
Credential Management API [Feat] [Tests]	Auto
Web Cryptography [Feat] [Tests]	Auto Test if crypto.subtle.generateKey is function
Encrypted Media Extensions [Feat] [Tests]	Auto Test for requestMediaKeySystemAccess in navigator Auto MediaKeys Test for MediaKeys in window
Passkeys [Feat] [Tests]	Auto Supports passkey creation Feature detection test from https://web.dev/passkey-registration/#feature-detection Interact Test passkey login here
Permissions API [Feat] [Tests]	Auto Test for 'permissions' in navigator Interact test here
Permissions Policy [Feat] [Tests]	Auto document.permissionsPolicy Interact Interact
Web Authentication API [Feat] [Tests]	Auto Test for the existance of the following interfaces: 'CredentialsContainer', 'PublicKeyCredential', 'AuthenticatorResponse', 'AuthenticatorAttestationResponse', 'AuthenticatorAssertionResponse'
Content Security Policy 1.0 [Feat] [Tests]	Visual-square iframe with file that will have lime background if external file is supported, but red again if the (CSP-blocked) inline script is supported. Prefixes are converted to known CSP header prefixes with support.
'SameSite' cookie attribute [Feat] [Tests]	Visual-square
ChaCha20-Poly1305 cipher suites for TLS [Feat] [Tests]	Interact Test here
Content Security Policy Level 2 [Feat] [Tests]	Interact Test here or here
HTTP Public Key Pinning [Feat] [Tests]	Interact test here
Referrer Policy [Feat] [Tests]	Interact Interact Test for content=never
Link type "noreferrer" [Feat] [Tests]	Interact
Server Name Indication [Feat] [Tests]	Interact test here
Strict Transport Security [Feat] [Tests]	Interact test here
Subresource Integrity [Feat] [Tests]	Interact test here
TLS 1.1 [Feat] [Tests]	Interact Test here
TLS 1.2 [Feat] [Tests]	Interact Test here
TLS 1.3 [Feat] [Tests]	Interact Test here
Upgrade Insecure Requests [Feat] [Tests]	Interact test here or here
X-Frame-Options HTTP header [Feat] [Tests]	Interact Test here
SVG (basic support) [Feat] [Tests]	Auto(m) Modernizr test for: "svg" Visual-square SVG in <object>
SVG effects for HTML [Feat] [Tests]	Auto Visual Text must appear blurry SVG with feGaussianBlur filter on foreignObject
Inline SVG in HTML5 [Feat] [Tests]	Auto(m) Modernizr test for: "inlinesvg" Visual-square Test CSS transform on SVG Visual-square
SVG SMIL animation [Feat] [Tests]	Auto(m) Modernizr test for: "smil" Visual-square SVG with animate element inside a rect Visual-square Inline SVG with animate element inside a rect
SVG in CSS backgrounds [Feat] [Tests]	Visual Must not look pixelated/blurry SVG CSS background image at 250% Visual-square Visual-square Tiled 5x5 SVG image as background Visual-square Tiled 5x5 SVG image as background with background-position
SVG filters [Feat] [Tests]	Visual Visual-square Must be green (not lime) SVG with <feColorMatrix type="hueRotate" values="120"/> Visual-square SVG with <feFlood flood-color="lime"/>
SVG fragment identifiers [Feat] [Tests]	Visual-square SVG image as background pointing at small lime square: svg-icons.svg#lime-view Visual-square SVG image as background pointing at small lime square with file: svg-icons.svg#svgView(viewBox(100,200,5,5)) Visual-square SVG image in img element pointing at small lime square with file: svg-icons.svg#svgView(viewBox(100,200,5,5)) Visual-square SVG image as background pointing at small lime square (id on rect element, no view element): svg-icons-noview.svg#lime-view
SVG in HTML img element [Feat] [Tests]	Visual-square Test for SVG image with embedded PNG Visual-square
SVG vector-effect: non-scaling-stroke [Feat] [Tests]	Visual-square Test for vector-effect="non-scaling-stroke"
SVG favicons [Feat] [Tests]	Interact Test page
SVG fonts [Feat] [Tests]	Visual Windsong font
CSS3 attr() function for all properties [unoff] [Feat] [Tests]	Test background-color: attr(data-color)
CSS Canvas Drawings [unoff] [Feat] [Tests]	Auto 'getCSSCanvasContext' in document
CSS Environment Variables env() [unoff] [Feat] [Tests]	Auto CSS.supports test for env(foo, 10px) Interact Test here
CSS overflow: overlay [unoff] [Feat] [Tests]	Auto overflow: overlay; value "sticks" Auto Test if getComputedStyle returns "overflow"
CSS Reflections [unoff] [Feat] [Tests]	Auto(m) Modernizr test for: "cssreflections" Visual-square box-reflect: below 0;
High-quality kerning pairs & ligatures [unoff] [Feat] [Tests]	Auto Test if text-rendering: optimizeLegibility will result in smaller width on text 'AVAVAVAVAVAVAVAV'
CSS -webkit-user-drag property [unoff] [Feat] [Tests]	Auto -webkit-user-drag: none; property "sticks" Interact This link should be undraggable This div should be draggable
CSS text-stroke and text-fill [unoff] [Feat] [Tests]	Visual green stroked text text-stroke: 2px lime; Visual green stroked text -webkit-text-stroke -webkit-text-stroke: 2px lime;
background-position-x & background-position-y [unoff] [Feat] [Tests]	Visual-square Test for background-position-x:30px; Visual-square Test for background-position-y:30px;
Explicit descendant combinator >> [unoff] [Feat] [Tests]	Visual-square
:focus-within CSS pseudo-class [unoff] [Feat] [Tests]	Interact Should turn lime on focus
Background-clip: text [unoff] [Feat] [Tests]	Auto -webkit-background-clip: text Auto background-clip: text Visual Text should be blue on white background -webkit-background-clip: text
CSS pointer-events (for HTML) [unoff] [Feat] [Tests]	Auto Interact SVG: click should turn it to lime
CSS text-size-adjust [unoff] [Feat] [Tests]	Auto text-size-adjust: none; property stays
CSS font-smooth [unoff] [Feat] [Tests]	Visual should appear lighter should appear bolder Visual should appear lighter should appear bolder Test for osx-font-smoothing
CSS Backdrop Filter [unoff] [Feat] [Tests]	Visual-square backdrop-filter: invert(1);

color-adjust

Test color-adjust: exact

Auto

print-color-adjust

Test print-color-adjust: exact

CSS Container Queries (Size)

[Feat] [Tests]

Auto

CSS Container Style Queries

[Feat] [Tests]

Auto

Test for CSS custom property: @container style(--works: true)

Auto

Test for regular CSS value: @container style(font-weight: bold)

[Feat] [Tests]

Auto

CSS.supports test for content-visibility: hidden

CSS position:fixed

[Feat] [Tests]

Auto

Interact

Test here

CSS font-palette

[Feat] [Tests]

Auto

CSS.supports test for font-palette: normal

CSS font-stretch

[Feat] [Tests]

Auto

font-stretch: condensed; property stays

Visual

Expanded
Condensed

[Feat] [Tests]

Auto

letter-spacing CSS property

[Feat] [Tests]

Auto

AAAAAAAAAAA

Test for fractional letter-spacing

Visual-square

Visual

HOTEL

Text should be vertical, but upright

CSS text-wrap: balance

[Feat] [Tests]

Auto

CSS.supports test for text-wrap: balance

Auto

text-wrap-style

a a a a

Test for orphans: 9

Visual-square

a a a a

CSS user-select: none

[Feat] [Tests]

Auto

user-select: none; property "sticks"

Interact

This text should be unselectable by the user.

user-select: none;

CSS will-change property

[Feat] [Tests]

Auto

will-change: contents; property stays

:indeterminate CSS pseudo-class

[Feat] [Tests]

Visual

::placeholder CSS pseudo-element

[Feat] [Tests]

Visual

Placeholder should be lime

::placeholder { color: lime; background-color: lime; opacity: 1 } (double colon)

Visual

Placeholder should be lime

:placeholder { color: lime; background-color: lime; opacity: 1 } (single colon)

Visual

Placeholder should be lime

text - weight: 200
text - weight: 900

CFF2 format

Visual

text - weight: 200
text - weight: 900

CFF2 format (AdobeVFPrototype)

CSS Masks

[Feat] [Tests]

Visual

mask-image: url(alpha.png);

CSS all property

[Feat] [Tests]

Visual-square

Test for all:inherit

CSS :any-link selector

[Feat] [Tests]

Visual-square

Visual-square

Case-insensitive CSS attribute selectors

Test color(xyz 0 1 0);

cqmax

Test for width:100cqmax; height:100cqmax;

CSS Cross-Fade Function

[Feat] [Tests]

Visual-square

Test for cross-fade(url(green64x64.png), url(red30x30.png), 0%);

Visual-square

Test for cross-fade(url(red30x30.png), url(green64x64.png), 100%)

:dir() CSS pseudo-class

[Feat] [Tests]

Visual-square

CSS display: contents

[Feat] [Tests]

Visual-square

Visual-square

:in-range and :out-of-range CSS pseudo-classes

[Feat] [Tests]

Visual-square

LCH and Lab color values

[Feat] [Tests]

Visual-square

lch(87.74% 119.78 136.02)

Visual-square

lab(87.74% -86.18 83.18)

CSS line-clamp

[Feat] [Tests]

Visual-square

a a a a a a a a a a a a a a a a a a a a a a a a a a a

CSS Nesting

[Feat] [Tests]

Visual-square

Test for nested "&"

Visual-square

@nest

Test for nested "@nest &"

selector list argument of :not()

[Feat] [Tests]

Visual-square

Visual-square

length

text-indent: 30px;

Visual-square

each-line

text-indent: 30px each-line;

Visual-square

hanging

flexbox

Visual test for justify-content: space-evenly support in flexbox

Visual-square

grid

justify-content: space-evenly in a grid

dvw

Test for gap: 30px;

Visual-square

row-gap

Test for row-gap: 30px;

Visual-square

Visual

topleft

topright

bottomleft

bottomright

CSS inline-block

[Feat] [Tests]

Visual-square

CSS3 selectors

[Feat] [Tests]

Should be lime when box is checked

Test for :checked support

Interact

Test here

text-emphasis styling

[Feat] [Tests]

[Feat] [Tests]

Auto(m)

Modernizr test for: "borderimage"

Visual

Must include 2 or 3 full horizontal yellow diamonds

Test for "round" - longhand

Visual

Must include full horizontal yellow diamonds w/spaces

Test for "space"

Visual-square

Separate properties: border-image-source: url(green5x5.png); border-image-slice: 2;

Visual-square

Shorthand syntax: border-image: url(green5x5.png) 2;

CSS3 Border-radius (rounded corners)

[Feat] [Tests]

Auto(m)

Modernizr test for: "borderradius"

Test image-orientation: from-image

Visual-square

Test image-orientation: 180deg

Visual-square

Visual

font-size: 25px; color: white; text-shadow: 25px 0 3px lime; position: relative; left: -25px;

Visual

Multiple shadow test

Visual-square

IIIII

Multiple shadows with radius value

CSS3 Transitions

[Feat] [Tests]

Auto(m)

Modernizr test for: "csstransitions"

Auto

transition-timing-function: steps(4, end) property "sticks"

Interact

Green square must (briefly) appear on hover

5 second transition from left to right using cubic-bezier(0, 1, 1, 0);

CSS3 Colors

[Feat] [Tests]

Auto(m)

Modernizr test for: "hsla"

backface-visibility

CSS.supports test for backface-visibility: visible

Visual-square

Parent: perspective: 100px; perspective-origin: 0% 50%; Child: transform: rotateY(-15deg);

@font-face Web fonts

[Feat] [Tests]

Auto(m)

Modernizr test for: "fontface"

CSS Counter Styles

[Feat] [Tests]

Visual

Should say "PASS"

Interact

Test here

Crisp edges/pixelated images

[Feat] [Tests]

Visual

img / bg / canvas

Test for image-rendering: crisp-edges

Visual

img / bg / canvas - must be crisp

Test for non-standard interpolation-mode: nearest-neighbor;

Visual

img / bg / canvas - must be crisp

Test for image-rendering: optimize-contrast; (non-standard)

Visual

img / bg / canvas - must be crisp

Test for image-rendering: pixelated;

CSS ::marker pseudo-element

[Feat] [Tests]

Visual

should say "PASS" and be colored green

[Feat] [Tests]

Visual

abcdefghijklmnopqrstuvwxyz

Should end with ellipsis

text-overflow: ellipsis;

CSS Generated content for pseudo-elements

[Feat] [Tests]

Visual

Element with CSS: #gencontent:before { content: 'A'; } #gencontent:after { content: 'Z'; }

CSS font-feature-settings

[Feat] [Tests]

Visual

LORE

Combine L&O and R&E (current syntax)

Current syntax: font-feature-settings: "dlig" 1;

Visual

LORE

Combine L&O and R&E (old syntax)

abc def

CSS Filter Effects

[Feat] [Tests]

Visual-square

filter: invert(1);

Visual-square

filter: url(css-filter.svg#invert);

CSS Hyphenation

[Feat] [Tests]

Visual-square

hyphenation

Test for hyphens: none

Visual-square

hyphenation

Test for hyphens: auto

Visual-square

hyphenation

width: min-content

Visual-square

width: min-intrinsic

Visual-square

max-content

width: max-content

Visual-square

fit-content()

width: fit-content(30px)

Interact

Test here

flex-basis

flex-basis: max-content

CSS3 object-fit/object-position

[Feat] [Tests]

Visual-square

Visual-square

aaabbbcccdddeeefff

Test for word-break: break-all;

Visual-square

这是一些汉字

Test for word-break: keep-all;

CSS3 Overflow-wrap

[Feat] [Tests]

Visual-square

abcdefghijklmnop

grab

grabbing

CSS3 Cursors: zoom-in & zoom-out

[Feat] [Tests]

Interact

Interact

Test here

Window.devicePixelRatio

[Feat] [Tests]

Auto

EventTarget.dispatchEvent

[Feat] [Tests]

Auto

[Feat] [Tests]

Auto

Validates once DOMContentLoaded is triggered

DOMMatrix

[Feat] [Tests]

Auto

DOMMatrix

Test for DOMMatrix in window

Auto

WebKitCSSMatrix

Test for WebKitCSSMatrix in window

Auto

CSSMatrix

Test for CSSMatrix in window

Auto

Methods

Test if DOMMatrix methods exist

Auto

Test if DOMMatrix is used in SVG

Auto

Static methods

Element.insertAdjacentElement() & Element.insertAdjacentText()

[Feat] [Tests]

Auto

insertAdjacentElement

Test for 'insertAdjacentElement' in document.body

Auto

insertAdjacentText

Test for 'insertAdjacentText' in document.body

"once" event listener option

[Feat] [Tests]

Auto

Auto

el.attachShadow

Test for 'attachShadow' in document.body

Auto

Visual-square

DPR

Test if "DPR" header is returned

Visual-square

Width

Test if "Width" header is returned

Visual-square

Viewport-Width

KeyboardEvent.location

[Feat] [Tests]

Interact

Type "a"

Test if event.location for the "a" key returns 0

Interact

Type "a"

Should start on "3"

Interact

xywh=50,50,50,50

theme-color Meta Tag

[Feat] [Tests]

Interact

Test this page

Audio element

[Feat] [Tests]

Auto

document.createElement('audio').canPlayType

Interact

Audio element with 6 different sources (no MIME set)

Interact

Custom Elements (V1)

[Feat] [Tests]

Auto

window.customElements.define

Test for customElements.define in window

Auto

Customized built-in element

dataset & data-* attributes

[Feat] [Tests]

Auto

Test for 'dataset' in document.body and getting the correct value returned from a data-foo attribute.

Visual-square

Test .dataset on SVG

Interact

Test here

Details & Summary elements

[Feat] [Tests]

Auto

Interact

(summary button)

(detail contents)

"(detail contents)" should be visible ONLY after clicking summary

Basic details element with summary and paragraph as children.

Dialog element

Visual-square

Test for iframe with srcdoc having lime background

naturalWidth & naturalHeight image properties

[Feat] [Tests]

Auto

Test for "loading" property in img element

Auto

iframe

[Feat] [Tests]

Auto

On:
Off:

Interact

Video with controls and all three formats available.

Interact

fail

meter widget at 50%

progress element

[Feat] [Tests]

Visual

fail

Progress widget at 50%

Visual

fail

Indeterminate progress widget

Picture element

[Feat] [Tests]

Visual-square

Must only accept audio files

Interact

sample png sample jpg

Test for :valid, :invalid with pattern attribute

Interact

Form should only submit if value is "pass"

Array.prototype.find

[Feat] [Tests]

Auto

Simple array.find() test

Array.prototype.findIndex

[Feat] [Tests]

Auto

localeCompare()

[Feat] [Tests]

Auto

Auto

Create a promise and test finally

Shared Array Buffer

[Feat] [Tests]

Auto

Test for SharedArrayBuffer without COOP/COEP enabled

Test for 'SharedArrayBuffer' in window

Interact

Test here

Test for SharedArrayBuffer with COOP/COEP enabled

JavaScript modules via script tag

[Feat] [Tests]

Visual-square

Test module in iframe

Visual-square

Interact

Test here

External test suite

Can request "clipboard-write" permission

Interact

First copy text from input field:

Test readText() method

Base64 encoding and decoding

[Feat] [Tests]

Auto

Test if window.btoa and window.atob work

Web Audio API

[Feat] [Tests]

Auto

Pasting text should turn background lime

Test if document.onpaste is triggered and has clipboardData

Interact

Pasting text should turn background lime (IE)

Test if window.onpaste is triggered and window.clipboardData has data (IE proprietary)

Interact

select this

Paste here:

Test for 'paintWorklet' in window.CSS

Visual-square

CSS.supports() API

[Feat] [Tests]

Auto

two arguments

Test for CSS.supports("color", "lime");

Auto

supportsCSS

Test for supportsCSS("color", "lime");

Auto

single argument condition

Clicking button should send request to go into full screen mode

Test requestFullscreen

Gamepad API

[Feat] [Tests]

Auto

Test for 'Gamepad' in window

Geolocation

[Feat] [Tests]

Auto(m)

Modernizr test for: "geolocation"

Auto

Test for getCurrentPosition, watchPosition and clearWatch in navigator.geolocation

Interact

Must show a notification

Create notification

Object RTC (ORTC) API for WebRTC

[Feat] [Tests]

Auto

[Feat] [Tests]

Auto

window.URLSearchParams

Test for 'URLSearchParams' in window

Auto

.get()

[Feat] [Tests]

Create a new Worker using new Worker('worker.js'); Then, test postMessage and onmessage event.

WebXR Device API

[Feat] [Tests]

Auto

xr.supportsSession

[Feat] [Tests]

Must turn lime on click or tap

Tests support for "pointerdown" event

Interact

Must turn lime on "pointerover"

Auto

audio

Test for 'captureStream' in document.createElement('audio')

Auto

Auto

HEIF/HEIC image format

[Feat] [Tests]

Visual

HEIF image

MathML

[Feat] [Tests]

Visual

AVIF image format

[Feat] [Tests]

Visual-square

30x30 lime avif image

Visual-square

must animate

animated avif image

Visual-square

lossy

lossy lime avif image

Visual-square

lossless

lossless lime avif image

Data URIs

[Feat] [Tests]

30x30 lime jpegxr image

Visual-square

30x30 lime lossless jpegxr image

SDCH Accept-Encoding/Content-Encoding

[Feat] [Tests]

Visual-square

WebP image format

[Feat] [Tests]

Visual-square

5x5 lime webp image sized at 30x30

asm.js

[Feat] [Tests]

Interact

Test here (result should be significant difference)

Brotli Accept-Encoding/Content-Encoding

[Feat] [Tests]

Interact

test here

content-encoding: brotli

Interact

test here

zstd (Zstandard) content-encoding

[Feat] [Tests]

Interact

Test here

Interact

Video with source element and MIME set

Interact

Video with source element

Interact

Video, no MIME, no type attribute.

Ogg/Theora video format

[Feat] [Tests]

Auto

Interact

Video with source element and MIME set

Interact

Video with source element

Interact

Video, no MIME, no type attribute.

WebM video format

[Feat] [Tests]

Auto

mkv

Interact

opus mp4

Interact

aac mp4

HEVC/H.265 video format

[Feat] [Tests]

Interact

WebVTT - Web Video Text Tracks

[Feat] [Tests]

Test here

Animated PNG (APNG)

[Feat] [Tests]

Auto

Test for second frame using Canvas element

Visual

Web Cryptography

[Feat] [Tests]

Auto

Test if crypto.subtle.generateKey is function

[Feat] [Tests]

Auto

Test for 'permissions' in navigator

Interact

test here

Permissions Policy

[Feat] [Tests]

Auto

document.permissionsPolicy

Interact

[Feat] [Tests]

Visual

Text must appear blurry

SVG with feGaussianBlur filter on foreignObject

Inline SVG in HTML5

[Feat] [Tests]

Auto(m)

Modernizr test for: "inlinesvg"

Visual-square

Test CSS transform on SVG

Visual-square

SVG SMIL animation

SVG image in img element pointing at small lime square with file: svg-icons.svg#svgView(viewBox(100,200,5,5))

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SVG image as background pointing at small lime square (id on rect element, no view element): svg-icons-noview.svg#lime-view

SVG in HTML img element

[Feat] [Tests]

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Test for SVG image with embedded PNG

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CSS3 attr() function for all properties [unoff]

Auto

-webkit-user-drag: none; property "sticks"

Interact

This link should be undraggable

This div should be draggable

CSS text-stroke and text-fill [unoff]

[Feat] [Tests]

Visual

green stroked text

text-stroke: 2px lime;

Visual

green stroked text

-webkit-text-stroke

-webkit-text-stroke: 2px lime;

background-position-x & background-position-y [unoff]

[Feat] [Tests]

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Test for background-position-x:30px;

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Test for background-position-y:30px;

Explicit descendant combinator >> [unoff]

[Feat] [Tests]

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:focus-within CSS pseudo-class [unoff]

[Feat] [Tests]

Interact

Should turn lime on focus

Background-clip: text [unoff]

[Feat] [Tests]

text-size-adjust: none; property stays

CSS font-smooth [unoff]

[Feat] [Tests]

Visual

should appear lighter

should appear bolder

Visual

should appear lighter

should appear bolder

Selectlist - Customizable select element [unoff]

[Feat] [Tests]

Auto

Scoped attribute [unoff]

[Feat] [Tests]

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If the scoped attribute is ignored, the box will get a red background.

Context menu item (menuitem element) [unoff]

[Feat] [Tests]

Interact

Context menu of square must have a "TEST PASS" entry

Uses "menuitem" child elements

Decorators [unoff]

[Feat] [Tests]

Auto

Syntax test for: class Example { @reactive accessor myBool = false; }

Auto

Test decorator

Object.observe data binding [unoff]

[Feat] [Tests]

Auto

Import maps [unoff]

[Feat] [Tests]

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Background Sync API [unoff]

[Feat] [Tests]

Auto

Test for 'SyncManager' in window

Cookie Store API [unoff]

[Feat] [Tests]

Auto

Test for cookieStore in window

Auto

(https only)

Test for 'usb' in navigator

Auto

Test various USB* properties in window

WebVR API [unoff]

[Feat] [Tests]

Auto

getVRDevices

Test for getVRDevices

Auto

getVRDisplays

Test for navigator.getVRDisplays

Auto

vr.getDisplays

Test for navigator.vr.getDisplays

Element.scrollIntoViewIfNeeded() [unoff]

[Feat] [Tests]

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scrollIntoViewIfNeeded()

Directory selection from file input [unoff]

[Feat] [Tests]

Interact

must allow directory to be selected

Test for webkitdirectory & "webkitRelativePath" property on files

Speech Synthesis API [unoff]

[Feat] [Tests]

Auto

Test if "speechSynthesis" in window is an object

Interact

Clicking button should make browser speak

Speak using: var speak = new SpeechSynthesisUtterance('hello'); speak.lang = 'en-GB'; window.speechSynthesis.speak(spk);

HTTP Live Streaming (HLS) [unoff]

[Feat] [Tests]

Auto

Auto

Document Policy [unoff]

[Feat] [Tests]

Auto

"policy" attribute in iframes

Feature Policy [unoff]

[Feat] [Tests]

Auto

document.featurePolicy

Interact

Trusted Types for DOM manipulation [unoff]

[Feat] [Tests]

Auto

FIDO U2F API [unoff]

[Feat] [Tests]

Interact

Currently untestable, hopefully this will stay up to date on info until it is.

IntersectionObserver V2 [unoff]

[Feat] [Tests]

Auto

User agent: Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)

The Can I use... test suite

Resource Hints: dns-prefetch

Text API for Canvas

Auto(m)

WebGL - 3D Canvas graphics

Auto(m)

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Canvas blend modes

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WebGL 2.0

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CSS image-set

CSS background-attachment

Auto

Auto

Interact

Interact

CSS Anchor Positioning

Auto

CSS Appearance

Auto

CSS caret-color

Auto

Interact

CSS print-color-adjust

Auto

Auto

CSS Container Queries (Size)

Auto

CSS Container Style Queries

Auto

Auto

CSS Containment

Auto

Auto

Auto

Auto

Auto

CSS content-visibility

Auto

CSS position:fixed

Auto

Interact

CSS font-palette

Auto

CSS font-stretch

Auto

Visual

CSS hanging-punctuation

Auto

Auto

Visual

CSS Initial Letter

Auto

Auto

Auto

CSS initial value

Auto

letter-spacing CSS property

Auto

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CSS Motion Path

Auto

Auto

Auto

Auto

CSS overflow property

Auto

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CSS overscroll-behavior

Auto

Auto

CSS page-break properties

Auto

Auto

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