August 2026 browser releases

Chrome 152 and Firefox 154 both shipped to stable during August 2026, while Safari had no stable release. Chrome 153 and Firefox 155 entered beta; Safari likewise had no beta. Several features reached Baseline Newly available.

CSS: Baseline arrivals

The text-box family

Firefox 154 implements text-box-trim, text-box-edge, and the text-box shorthand, giving control over text alignment and spacing in the block direction. Font metrics commonly carry extra vertical space above and below glyphs as leading and half-leading, which produces uneven vertical alignment and unexpected spacing around headings or icons. text-box-edge selects the font metric to trim to, such as cap alphabetic or ex alphabetic; text-box-trim chooses the over edge, the under edge, or both. The shorthand merges the two. With prior support in Safari 18.2 and Chrome 133, the properties are Baseline Newly available.

Rachel Andrew

sibling-count() and sibling-index()

Also new in Firefox 154, these CSS functions remove the need for JavaScript or utility classes when computing dynamic values. sibling-count() returns an integer for the total number of sibling DOM elements in the parent container, counting the element itself. sibling-index() returns the current element's 1-based position among its siblings. Typical uses are layout sizes, staggered animation delays, and color variations. Both are Baseline Newly available.

Chrome 152 additions

The global autocorrect attribute

Chrome 152 supports the autocorrect HTML attribute, reflected on HTMLElement.prototype.autocorrect. It governs automatic spelling and punctuation correction on editable elements — <input>, <textarea>, and contenteditable elements — and accepts on and off. Safari and Firefox already supported it, so the attribute is now Baseline Newly available.

CSSPseudoElement extended

CSSPseudoElement, previously covering ::after, ::before, and ::marker, now also covers ::backdrop, ::scroll-marker, and ::view-transition. Attaching listeners to the ::backdrop pseudo-element makes it possible to close a dialog on a click outside its content without computing coordinate bounding boxes. For ::scroll-marker it enables capturing user interaction events; for ::view-transition it allows intercepting transitions or building geometry-aware animations.

alpha() and window-drag

The alpha() function from CSS Color 5 produces relative alpha colors: given an origin color, it returns that color with an adjusted alpha channel, keeping the color channels intact and working in any color space.

window-drag standardizes and renames the older app-region property, taking the values move and none with standard CSS inheritance. In installed desktop web applications it marks layout areas such as custom title bars or headers as draggable, so a pointer drag moves the top-level application window instead of scrolling or selecting page content.

OpaqueRange

Chrome 152 introduces OpaqueRange, a live text range scoped to form control values such as <textarea> and text-based <input> elements. It lets range-based APIs — getBoundingClientRect(), getClientRects(), and the CSS Custom Highlight API — work on form control text for inline suggestions, spelling highlights, and anchored popovers. Component encapsulation is preserved because it exposes value offsets rather than internal shadow tree container nodes.

Firefox 154: JavaScript and WebRTC

Iterator helpers

  • includes(): reports whether an iterator produces a given value, returning true or false.
  • join(): concatenates all produced elements into a string with a delimiter, like Array.prototype.join().
  • chunks(): returns a helper iterator yielding consecutive fixed-size array chunks.
  • windows(): returns a helper iterator yielding a sliding window array.

WebRTC transport

  • RTCIceTransport.getSelectedCandidatePair() and the selectedcandidatepairchange event expose the currently active ICE candidate pair.
  • The error event on RTCDtlsTransport surfaces DTLS transport and fingerprint errors.
  • rtcp configuration parameters are supported on RTCRtpReceiver.getParameters() and RTCRtpSender.getParameters().
  • Transport statistics now report RTCCertificateStats and additional RTCTransportStats.

With Chrome and Safari already shipping them, RTCIceTransport.getSelectedCandidatePair() and the RTCDtlsTransport error event are Baseline Newly available.

In beta

Chrome 153 beta brings single-axis scroll containers (overflow: scroll clip) and the scroll-axis-lock CSS property to prevent gesture axis locking, along with TC39 Iterator join() and joint iteration (zip) in JavaScript. Its Web API additions are the dedicated single-capability declarative elements <camera> and <microphone>.

Firefox 155 beta updates SVGAElement to implement HyperlinkElementUtils, so SVG <a> elements expose origin and the standard URL properties protocol, hostname, pathname, search, and hash. It also adds indexed setters to the SVG list interfaces SVGNumberList, SVGPointList, SVGStringList, and SVGTransformList.