Discover some of the interesting features that have landed in stable and beta
web browsers during September 2025.
Published: October 1, 2025
Stable browser releases
Chrome 140, Chrome 141, Safari 26, and Firefox 143
released to stable during September, this post takes a look at what has been a pretty exciting month for the web platform.
New CSS features in Safari 26
There’s a lot to see in the latest Safari release, there’s a comprehensive
write-up in WebKit Features in Safari 26.0.
Some top highlights for CSS include the following features.
Anchor positioning
As part of Interop 2025, Safari has shipped support for
CSS anchor positioning.
This lets you tether elements to an anchor, and is particularly useful when
combined with popover.
text-wrap: pretty
The pretty value of text-wrap asks the browser to improve typography—for
example, reducing the impact of ragged edges and typographic rivers,
and preventing short last lines.
Scroll-driven animations
Safari also ships support for scroll-driven animations, letting you tie
animations to how far the user has scrolled.
New values and functions
Safari is the first browser to add support for the contrast-color() function, giving you a way to
ask the browser to select the color with the most contrast against another color.
The progress() math function returns a number indicating the progress between two other values.
The align-self and justify-self properties for absolute positioning are now supported.
The logical properties overflow-block and overflow-inline are supported, and can be used in place of overflow-x and overflow-y.
Safari also now supports margin-trim.
The ::details-content pseudo-element
Firefox 143 adds support for ::details-content, this lets you style the content
of the <details> element.
Support for styling markers created with generated content
Firefox 143 also adds support for the ::before::marker and ::after::marker selectors.
These let you style a ::marker when it was created using the ::before or ::after
pseudo-element.
Digital Credentials API
Safari 26 and Chrome 141 includes support for the Digital Credentials API. This lets websites selectively request verifiable information about the user through digital credentials such as a driver’s license or a national identification card stored in a digital wallet.
The URL Pattern API becomes Baseline Newly available
The URL Pattern API lets you use the
URL Pattern Standard to match URLs
using regular expressions. It shipped in Safari 26, and is now Baseline Newly available.
Uint8Array to and from base64 and hex is now Baseline Newly available
Base64 is a common way to represent arbitrary binary data as ASCII. JavaScript has Uint8Arrays for binary data. However, it lacks a built-in mechanism to encode that data as base64, or to take base64 data and produce a corresponding Uint8Array. This feature adds the ability and methods for converting between hex strings and Uint8Arrays. With Chrome 140, it becomes Baseline Newly available.
The caret-animation property
The CSS caret-animation property shipped in Chrome 140 and has two possible values: auto and manual. auto means browser default (blinking), and manual means the developer controls the caret animation. Additionally, users who are disturbed by or have adverse reactions to blinking or flashing visuals can disable the blinking with a user stylesheet.
The ARIA Notify API
From Chrome 141, ariaNotify provides a JavaScript API that lets content authors tell a screen reader what to read.
It improves reliability and developer control compared to ARIA live regions, allowing for announcing changes not tied to DOM updates.
IndexedDB getAllRecords() and direction option for getAll() and getAllKeys()
This feature in Chrome 141 adds the getAllRecords() method to the IndexedDB IDBObjectStore and IDBIndex. It also adds a direction parameter to getAll() and getAllKeys(). This functionality lets certain read patterns be significantly faster when compared to the existing alternative of iteration with cursors.
Beta browser releases
Beta browser versions give you a preview of things that will be in the next
stable version of the browser. It’s a great time to test new features, or
removals, that could impact your site before the world gets that release.
New betas this month are
Firefox 144 and
Safari 26.1.
Safari 26.1 is mostly a bug fix release, with fixes to anchor positioning among other changes.
Firefox 144 will ship view transitions for Single-Page Apps (SPAs).
This is one of the focus areas for Interop 2025 and means that this feature
becomes Baseline Newly available.
Also included in Firefox 144 is the moveBefore() method on the Element, DocumentFragment and Document interfaces. This lets you move an immediate child element of the object, before another of its child elements.