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:
If you are interested in contributing tests, follow these instructions.
Show all features
|Feature||Unprefixed tests||Prefixed tests|
:optional CSS pseudo-class [unoff]
Test to ensure :optional does not apply to a required field
Most tests by Alexis Deveria, additional contributions by Paul IrishUser agent: CCBot/2.0 (https://commoncrawl.org/faq/)