# Safari Technology Preview 242 Release Notes Learn about the latest web technology updates in Safari Technology Preview: Accessibility, CSS, Forms, HTML, Images, JavaScript, Media, Networking, Rendering, SVG, Scrolling, Tables, Web API, and WebRTC. ## Overview [Safari Technology Preview](https://webkit.org/blog/6017/introducing-safari-technology-preview/) Release 242 is now [available for download](https://developer.apple.com/safari/resources/) for macOS Tahoe and macOS Sequoia. If you already have Safari Technology Preview installed, you can update it in System Settings under General → Software Update. This release includes WebKit changes between: [310187@main…310599@main](https://github.com/WebKit/WebKit/compare/f91abd9528154fcf24a3ea90d43fdde378d9793b...b53493b67d659fd4026d0a21d03b63620daf704e). ### Accessibility #### Resolved Issues - Fixed an issue where VoiceOver read text within images that have `role="presentation"`. ([310483@main](https://commits.webkit.org/310483@main)) (159304061) - Fixed macOS accessibility support for customizable `` elements using `appearance: base-select`. ([310441@main](https://commits.webkit.org/310441@main)) (173696010) ### CSS #### New Features - Added support for the CSS `attr()` function from CSS Values Level 5. ([310246@main](https://commits.webkit.org/310246@main)) (173700363) - Added support for the `oblique-only` value for `font-synthesis-style` as defined in CSS Fonts Level 4. ([310409@main](https://commits.webkit.org/310409@main)) (173730766) #### Resolved Issues - Fixed an issue where `@media (prefers-color-scheme: dark)` inside an iframe did not match when the iframe’s `color-scheme` was set to `dark`. ([310465@main](https://commits.webkit.org/310465@main)) (142072593) - Fixed `position-try-order` to interpret logical axis values using the containing block’s writing mode instead of the element’s own writing mode. ([310277@main](https://commits.webkit.org/310277@main)) (169501069) - Fixed an issue where percent-height replaced elements computed stale preferred widths in shrink-to-fit containers. ([310194@main](https://commits.webkit.org/310194@main)) (171184282) - Fixed an issue where the table cell `nowrap` minimum width calculation quirk was applied outside of quirks mode. ([310195@main](https://commits.webkit.org/310195@main)) (171410252) - Fixed an issue where checkbox outlines appeared misaligned. ([310323@main](https://commits.webkit.org/310323@main)) (172742551) - Fixed an issue where anchor-positioned elements anchored to children of sticky-positioned boxes did not stick correctly. ([310255@main](https://commits.webkit.org/310255@main)) (172884148) - Fixed an issue where pseudo-elements were not sorted correctly when sorting anchor elements by tree order. ([310407@main](https://commits.webkit.org/310407@main)) (173032203) - Fixed an issue where ligatures caused a non-zero layout width for text with `font-size: 0`. ([310394@main](https://commits.webkit.org/310394@main)) (173840866) - Fixed `:in-range` and `:out-of-range` pseudo-classes to correctly update when the `readonly` attribute changes. ([310484@main](https://commits.webkit.org/310484@main)) (173978657) - Fixed an issue where `view-timeline-inset` serialization failed to coalesce identical values. ([310590@main](https://commits.webkit.org/310590@main)) (174096313) ### Forms #### Resolved Issues - Fixed an issue where `` did not always fire `onchange` when the mouse button was released far outside the element. ([310482@main](https://commits.webkit.org/310482@main)) (173882861) ### HTML #### New Features - Added support for the `closedby` attribute on `

` elements. ([310487@main](https://commits.webkit.org/310487@main)) (173974767) #### Resolved Issues - Fixed the HTML parser fast path to correctly process escaped attribute values longer than one character. ([310209@main](https://commits.webkit.org/310209@main)) (173673581) - Fixed the HTML parser fast path to correctly detect nested `

` elements. ([310492@main](https://commits.webkit.org/310492@main)) (173983892) - Fixed the HTML parser fast path to use the adjusted current node for MathML and SVG integration point checks. ([310593@main](https://commits.webkit.org/310593@main)) (174096305) ### Images #### Resolved Issues - Fixed an issue where inserting an image with a `srcset` attribute into a dynamically created iframe resulted in an invisible image. ([310446@main](https://commits.webkit.org/310446@main)) (66849050) ### JavaScript #### Resolved Issues - Fixed an issue where class instance field initializers did not have the correct evaluation context when used inside arrow functions and nested scopes. ([310594@main](https://commits.webkit.org/310594@main)) (173296563) - Fixed `%ArrayIteratorPrototype%.next()` to return `{ done: true }` instead of throwing a `TypeError` when the source TypedArray is detached and the iterator has already completed. ([310292@main](https://commits.webkit.org/310292@main)) (173759106) - Fixed an issue where a fixed-count mixed-width character class in a regular expression did not correctly restore the index on backtrack. ([310477@main](https://commits.webkit.org/310477@main)) (173972458) ### Media #### Resolved Issues - Fixed an issue where scrubbing a video in full-screen mode could cause it to exit full-screen. ([310415@main](https://commits.webkit.org/310415@main)) (172682230) - Fixed an issue where `HTMLMediaElement.preservesPitch = true` did not work when the element was connected to an `AudioContext`. ([310521@main](https://commits.webkit.org/310521@main)) (173727365) ### Networking #### New Features - Added support for secure cookies on loopback hosts. ([310542@main](https://commits.webkit.org/310542@main)) (137604100) ### Rendering #### Resolved Issues - Fixed a regression where nested column flexboxes could cause content to render at the wrong size. ([310253@main](https://commits.webkit.org/310253@main)) (173321492) - Fixed a regression where nested empty inline boxes accumulated an incorrect vertical offset, causing inline elements to stack as block-level elements. ([310313@main](https://commits.webkit.org/310313@main)) (173723162) - Fixed an issue where pseudo-elements were incorrectly included in outline rect collection. ([310531@main](https://commits.webkit.org/310531@main)) (174033087) ### SVG #### New Features - Added support for the `lang` and `xml:lang` attribute in SVG. ([310495@main](https://commits.webkit.org/310495@main)) (143751056) #### Resolved Issues - Fixed an issue where SMIL animations of `href` or `xlink:href` on SVG `` elements had no visual effect. ([310236@main](https://commits.webkit.org/310236@main)) (96316808) - Fixed an issue where SVG gradient animations did not work unless `y1` and `y2` attributes were explicitly specified. ([310257@main](https://commits.webkit.org/310257@main)) (123457088) - Fixed an SVG `` positioning bug with `xml:space="preserve"` that caused multi-line text to render incorrectly. ([310347@main](https://commits.webkit.org/310347@main)) (143722975) - Fixed an issue where URL fragments were not percent-decoded before being used for SVG references. ([310443@main](https://commits.webkit.org/310443@main)) (169582378) ### Scrolling #### Resolved Issues - Fixed an issue where sticky-positioned elements could flicker rapidly after scrolling. ([310545@main](https://commits.webkit.org/310545@main)) (173680821) - Fixed an issue where scroll anchoring could cause a page to scroll to the top or bottom automatically. ([310574@main](https://commits.webkit.org/310574@main)) (173885027) ### Tables #### Resolved Issues - Fixed an issue with a collapsed border color mismatch when the table cell has a different writing-mode. ([310303@main](https://commits.webkit.org/310303@main)) (173655092) ### Web API #### New Features - Added support for `getAllRecords()` and `IDBGetAllOptions` in the IndexedDB API. ([310462@main](https://commits.webkit.org/310462@main)) (173881825) #### Resolved Issues - Fixed an issue where `document.open()` incorrectly aliased the caller’s security origin. ([310543@main](https://commits.webkit.org/310543@main)) (173369038) - Fixed an issue where `Object.prototype` could not be serialized by `structuredClone()`. ([310363@main](https://commits.webkit.org/310363@main)) (173728983) - Fixed an issue where backslashes were not handled correctly in non-special URLs. ([310290@main](https://commits.webkit.org/310290@main)) (173757759) - Fixed a URL parsing bug in the special relative or authority state. ([310300@main](https://commits.webkit.org/310300@main)) (173772241) - Fixed an issue where event listener `once` and `passive` flags were not preserved when copying listeners between elements. ([310355@main](https://commits.webkit.org/310355@main)) (173834642) - Fixed `Preserve existing listener options (such as passive defaulting) when overwriting event handler attributes. ([310362@main](https://commits.webkit.org/310362@main)) (173842822) ### WebRTC #### New Features - Added support for `RTCRtpReceiver.jitterBufferTarget`. ([310285@main](https://commits.webkit.org/310285@main)) (173676035) - Added support for video source `width` and `height` in RTC stats. ([310295@main](https://commits.webkit.org/310295@main)) (173677615) #### Resolved Issues - Fixed an issue where I420 BT709 `VideoFrame` was encoded in an incorrect color space when encoding to VP9. ([310306@main](https://commits.webkit.org/310306@main)) (169425608) - Fixed an issue where `RTCRtpSender.setParameters` did not clear parameters that were unset by the web application. ([310286@main](https://commits.webkit.org/310286@main)) (173678165) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)