Web platform features explorer

📃 December 2020 release notes

New in Firefox

The following features are now available in Firefox:

:not(): The :not() functional pseudo-class matches elements that do not match the selectors in its argument.
Paint timing: The paint performance entry and the PerformancePaintTiming API measures the duration of "paint" (also called "render") operations as a page loads. The API measures the time to First Paint (FP) and First Contentful Paint (FCP), common metrics for perceived loading times.

New in Firefox for Android

The following features are now available in Firefox for Android:

:not(): The :not() functional pseudo-class matches elements that do not match the selectors in its argument.
Paint timing: The paint performance entry and the PerformancePaintTiming API measures the duration of "paint" (also called "render") operations as a page loads. The API measures the time to First Paint (FP) and First Contentful Paint (FCP), common metrics for perceived loading times.