📃 January 2026 release notes

Newly available

The following features are newly available:

Active view transition: The :active-view-transition CSS pseudo-class matches the root element when a view transition is active. The :active-view-transition-type() CSS pseudo-class matches only when the active view transition was started with the specified type.
JavaScript modules in service workers: The navigator.serviceWorker.register() method accepts { type: "module" } to load scripts that use import and export. Also known as ECMAScript modules or ESM in service workers.
Navigation API: The navigation API initiates, intercepts, or modifies browser navigation actions. Not to be confused with the navigator API.
rcap unit: The rcap CSS length unit is a font-relative length equal to the value of the cap unit on the root element. Cap-height is approximately equal to the height of a capital Latin letter.
rch unit: The rch CSS length unit is a font-relative length equal to the value of the ch unit on the root element. ch length is based on the width of the zero (0) character.
rex unit: The rex CSS length unit is a font-relative length that is equal to the x-height of the root element.
ric unit: The ric CSS length unit, or root international character, is a font-relative length equal to the width of CJK character relative to the root element.

The following features are now widely available:

animation-composition: The animation-composition CSS property chooses how to combine animations that affect the same property.
Array by copy: The toReversed(), toSorted(), toSpliced(), and with() methods of arrays and typed arrays return changed copies of arrays. They stand in contrast to methods such as sort() or reverse() that change arrays in place.

The following features are now available in Chrome:

caret-shape: The caret-shape CSS property sets the shape of the insertion caret, the symbol that shows where the next character is to be inserted or deleted.
clipboardchange: The clipboardchange event for navigator.clipboard fires when the user modifies the clipboard's contents.
Temporal: The Temporal API allows you to work with dates, times, time zones, and durations. It is more powerful than the Date API.

The following features are now available in Chrome Android:

caret-shape: The caret-shape CSS property sets the shape of the insertion caret, the symbol that shows where the next character is to be inserted or deleted.
clipboardchange: The clipboardchange event for navigator.clipboard fires when the user modifies the clipboard's contents.
Temporal: The Temporal API allows you to work with dates, times, time zones, and durations. It is more powerful than the Date API.

The following features are now available in Firefox:

CSS import attributes: Module import … with { type: "css" } statements load CSS modules as constructable stylesheets. Also known as CSS module scripts.
Iterator.concat(): The Iterator.concat() JavaScript method returns an iterator that yields values from a sequence of iterators, exhausting each iterator before moving on to the next.

The following features are now available in Firefox for Android:

CSS import attributes: Module import … with { type: "css" } statements load CSS modules as constructable stylesheets. Also known as CSS module scripts.
Iterator.concat(): The Iterator.concat() JavaScript method returns an iterator that yields values from a sequence of iterators, exhausting each iterator before moving on to the next.