📃 January 2025 release notes

Newly available

The following features are newly available:

Popover: The popover HTML attribute creates an overlay to display content on top of other page content. Popovers can be shown declaratively using HTML, or using the showPopover() method.
Promise.try(): The Promise.try() static method returns a promise that takes a callback of any kind (returns or throws, synchronously or asynchronously) and wraps its result in a Promise.

The following features are now widely available:

Style containment: The contain: style CSS declaration permits the browser to avoid slower layout calculations by preventing modification to counter (counter-increment and counter-set) and quotation styles (content property quote values) beyond the element's descendants.

The following features are now available in Chrome:

Device posture: The device posture API provides information about the physical posture of a device, such as whether a foldable device is folded or unfolded.
Element capture: The restrictTo() method on screen capture media tracks limits capture to a specific element, excluding content which might occlude the element itself, such as video conferencing controls.

The following features are now available in Chrome Android:

Device posture: The device posture API provides information about the physical posture of a device, such as whether a foldable device is folded or unfolded.
File system access: The showOpenFilePicker(), showDirectoryPicker(), and showSaveFilePicker() methods request access to files and directories on the user's device and returns a handle for reading and writing to them.

The following features are now available in Edge:

Device posture: The device posture API provides information about the physical posture of a device, such as whether a foldable device is folded or unfolded.
Element capture: The restrictTo() method on screen capture media tracks limits capture to a specific element, excluding content which might occlude the element itself, such as video conferencing controls.

The following features are now available in Firefox:

RegExp.escape(): The RegExp.escape() static method takes a string and replaces any characters that are potentially special characters of a regular expression with equivalent escape sequences. For example, RegExp.escape("[abc]") returns "\\[abc\\]".
Memory64 (WebAssembly): Instructions accept 64-bit memory indexes.
String builtins (WebAssembly): The WebAssembly builtin string functions mirror a subset of the JavaScript String API and adapt it to be efficiently callable without JavaScript glue code.

The following features are now available in Firefox for Android:

RegExp.escape(): The RegExp.escape() static method takes a string and replaces any characters that are potentially special characters of a regular expression with equivalent escape sequences. For example, RegExp.escape("[abc]") returns "\\[abc\\]".
Memory64 (WebAssembly): Instructions accept 64-bit memory indexes.
String builtins (WebAssembly): The WebAssembly builtin string functions mirror a subset of the JavaScript String API and adapt it to be efficiently callable without JavaScript glue code.