New to the web platform in December

Discover some of the interesting features that have landed in stable and beta web browsers during December 2023.

Stable browser releases

In December 2023 Firefox 121, Chrome 120, and Safari 17.2 became stable. This post looks at what that means for the web platform.
Browser compatibility data pulled from MDN is included in these posts and may not have been updated yet for very recent browser releases. The post will show the correct information as soon as it appears in the browser-compat-data release.
Relaxed parsing for CSS Nesting

Chrome 120 and Safari 17.2 include relaxed parsing for CSS Nesting. As this has been supported in Firefox from version 117, this means that all major engines support this syntax change.
Exclusive accordions with the element

Chrome 120 and Safari 17.2 include support for the name attribute for the element. This means that you can create exclusive accordion components by grouping a number of elements.

Learn more in exclusive accordion.

Browser Support

The :has() selector

Firefox 121 includes the CSS :has() selector. This release makes :has() interoperable across all major engines.

Find out more in :has(): the family selector.

Browser Support

Source

The CSS Custom Highlight API

Safari 17.2 includes the CSS Custom Highlight API which lets you create and style text ranges, extending the standard highlight pseudo-classes such as ::selection.

Browser Support

105
105
17.2

Source

The CloseWatcher API

Chrome 120 includes the CloseWatcher API, a new API for listening for and responding to close requests. These requests are triggered by the ESC key on desktop and the back gesture or button on Android, and can be tricky to implement well.

In addition to the API, Chrome 120 upgrades and the popover attribute to respond to the Android back button.

Browser Support

CSS text-wrap: balance and stable

Firefox 121 includes the balance and stable values for text-wrap. The balance value is useful for short blocks of content such as headings, creating more pleasing and easy to read text. The stable value prevents editable content from relowing while being edited.

Learn more about text-wrap: balance.
text-wrap: balance

Browser Support