# Safari Technology Preview 249 Release Notes Learn about the latest web technology updates in Safari Technology Preview: Accessibility, Animations, CSS, Editing, Forms, HTML, JavaScript, Media, Rendering, Spatial Web, Web API, Web Audio, Web Inspector, WebAssembly, WebDriver, and WebRTC. ## Overview [Safari Technology Preview](https://webkit.org/blog/6017/introducing-safari-technology-preview/) Release 249 is now [available for download](https://developer.apple.com/safari/resources/) for macOS Golden Gate and macOS Tahoe. 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: [316531@main…317820@main](https://github.com/WebKit/WebKit/compare/402dc1b3bf265f5afd15d1b68374ef0885824299...82913509604940fdfe247e5da3609c6de6e44d89). ### Accessibility #### Resolved Issues - Fixed an issue where an `aria-labelledby` relation was not built when its target element was inserted via `innerHTML`. ([316913@main](https://commits.webkit.org/316913@main)) (179677418) - Fixed an issue where VoiceOver was silent during character navigation inside a local iframe. ([317264@main](https://commits.webkit.org/317264@main)) (182229891) - Fixed an issue where web content somtimes appeared empty to assistive technology after navigation. ([317449@main](https://commits.webkit.org/317449@main)) (182544199) ### Animations #### Resolved Issues - Fixed an issue where calling `play()` on a finite scroll-driven animation timeline did not reset its start time to the current time. ([316745@main](https://commits.webkit.org/316745@main)) (181712713) - Fixed an issue where `animation-timeline` did not use the last matching timeline when it matched multiple timelines. ([317330@main](https://commits.webkit.org/317330@main)) (182405676) - Fixed an issue where `animation-timeline` could match a timeline outside the nearest `timeline-scope` element with that name. ([317376@main](https://commits.webkit.org/317376@main)) (182417407) ### CSS #### New Features - Added support for the `attr()` function. ([316672@main](https://commits.webkit.org/316672@main)) (173992627) - Added support for `outline-offset: inset`. ([316677@main](https://commits.webkit.org/316677@main)) (180547604) - Added support for the `@function` custom functions rule. ([316671@main](https://commits.webkit.org/316671@main)) (181625123) - Added preview support for the `wrap-inside` property. ([317182@main](https://commits.webkit.org/317182@main)) (181751564) - Added support for the `if()` function. ([316813@main](https://commits.webkit.org/316813@main)) (181806268) - Added support for `calc-mix()`. ([316847@main](https://commits.webkit.org/316847@main)) (181839626) - Added support for `justify-self` on block-level boxes. ([317212@main](https://commits.webkit.org/317212@main)) (181926245) - Added preview support for `text-decoration-inset`. ([317230@main](https://commits.webkit.org/317230@main)) (182019037) - Added preview support for the `content` property on the `::marker` pseudo-element. ([317211@main](https://commits.webkit.org/317211@main)) (182066124) #### Resolved Issues - Fixed an issue where setting `view-transition-name` dynamically did not create a stacking context. ([317310@main](https://commits.webkit.org/317310@main)) (178316558) - Fixed an issue where CSS Grid items with a computed preferred size that behaves as `auto` did not correctly compute their minimum content contribution. ([316697@main](https://commits.webkit.org/316697@main)) (181146154) - Fixed an issue where visually overflowing content in a CSS Grid item was not painted. ([316668@main](https://commits.webkit.org/316668@main)) (181277780) - Fixed `anchor-center` in vertical writing modes not being scroll-adjusted along the block axis. ([316537@main](https://commits.webkit.org/316537@main)) (181413103) - Fixed an issue where an empty editable flex container did not reserve a line’s worth of block size in vertical writing modes. ([317467@main](https://commits.webkit.org/317467@main)) (181485387) - Fixed an issue where CSS Grid did not correctly increase track sizes to accommodate items spanning flexible tracks. ([317426@main](https://commits.webkit.org/317426@main)) (181635324) - Fixed an issue where stretch alignment did not trigger stretch sizing for CSS Grid items. ([316949@main](https://commits.webkit.org/316949@main)) (181750071) - Fixed an issue where CSS Grid items could retain stale block sizes after a subsequent layout. ([317166@main](https://commits.webkit.org/317166@main)) (182144347) - Fixed an issue where `clip-path` shapes could render with incorrect arcs. ([317397@main](https://commits.webkit.org/317397@main)) (182443333) - Fixed an issue where `::highlight()` and `::target-text` ignored `text-underline-offset`. ([317440@main](https://commits.webkit.org/317440@main)) (182466757) - Fixed an issue where `::highlight()` decoration replaced the originating element’s decoration instead of layering over it. ([317439@main](https://commits.webkit.org/317439@main)) (182523249) ### Editing #### Resolved Issues - Fixed an issue that disallowed font names that were not a valid CSS identifiers. ([316948@main](https://commits.webkit.org/316948@main)) (51409819) - Fixed the Edit menu’s Copy item being incorrectly enabled when there was no selection in the web page. ([316571@main](https://commits.webkit.org/316571@main)) (176061974) ### Forms #### Resolved Issues - Fixed an issue where the `datalist` popup menu was presented in the wrong place on a screen to the left of the main screen. ([316965@main](https://commits.webkit.org/316965@main)) (181967418) ### HTML #### New Features - Added support for `popover=hint`. ([317402@main](https://commits.webkit.org/317402@main)) (129495028) ### JavaScript #### New Features - Added support for the `Temporal` object. ([316742@main](https://commits.webkit.org/316742@main)) (181723535) ### MathML #### Resolved Issues - Fixed an issue where U+2016 (DOUBLE VERTICAL LINE) was missing the symmetric property in the MathML operator dictionary. ([316867@main](https://commits.webkit.org/316867@main)) (179558196) ### Media #### Resolved Issues - Fixed an issue where finding text starting from a selection could resolve to the wrong caption cue instead of the one nearest the video’s playhead. ([317168@main](https://commits.webkit.org/317168@main)) (182001231) ### Rendering #### New Features - Added support for dark mode in the XML document viewer. ([316832@main](https://commits.webkit.org/316832@main)) (122234600) #### Resolved Issues - Fixed an issue where `box-shadow` rendering broke when the page was zoomed. ([317080@main](https://commits.webkit.org/317080@main)) (169167365) ### Scrolling #### Resolved Issues - Fixed an issue where re-snapping did not select the snap area aligned in both axes when multiple targets were aligned. ([317294@main](https://commits.webkit.org/317294@main)) (182285397) - Fixed an issue where `scroll-snap-align` was not respected when scrolling to an anchor or calling `scrollIntoView()`. ([317495@main](https://commits.webkit.org/317495@main)) (182544180) ### Spatial Web #### Resolved Issues - Fixed an issue where navigating back to a page with a previously active web environment left the UI stuck showing the environment as active. ([316891@main](https://commits.webkit.org/316891@main)) (180966321) - Fixed an issue where the background color of `HTMLModelElement` did not match spec for non-opaque colors. ([316788@main](https://commits.webkit.org/316788@main)) (181641249) ### Web API #### New Features - Added support for subgroups in WebGPU. ([317145@main](https://commits.webkit.org/317145@main)) (154874391) - Added support for close watchers, including the `closedby` attribute for `dialog` elements. ([316680@main](https://commits.webkit.org/316680@main)) (180105698) #### Resolved Issues - Fixed an issue where a user gesture authorization token was not properly verified for Digital Credentials requests. ([317228@main](https://commits.webkit.org/317228@main)) (174908839) - Fixed `DOMMatrix` and `IntersectionObserver` correctly enforcing absolute-length unit requirements when parsing values. ([316532@main](https://commits.webkit.org/316532@main)) (181453666) - Fixed an issue where Scroll To Text Fragment directives could run outside `text/html` and `text/plain` documents. ([316976@main](https://commits.webkit.org/316976@main)) (181763736) - Fixed an issue where `replaceChildren()` could not replace a document’s children. ([316909@main](https://commits.webkit.org/316909@main)) (181921026) ### Web Audio #### Resolved Issues - Fixed Web Audio `PannerNode` orientation-only changes not updating the directional cone gain. ([316541@main](https://commits.webkit.org/316541@main)) (181413407) ### Web Inspector #### New Features - Added support for the range mappings proposal in source maps. ([316748@main](https://commits.webkit.org/316748@main)) (178564308) - Added per-element `Layout Invalidated` events in Web Inspector to reflect the number of elements affected by a layout invalidation. ([317302@main](https://commits.webkit.org/317302@main)) (181243589) #### Resolved Issues - Fixed an issue where every `` element showed a Scroll badge in the Elements tab. ([316773@main](https://commits.webkit.org/316773@main)) (101661656) - Fixed an issue where search results did not select the corresponding source code line for fetched JSON. ([317499@main](https://commits.webkit.org/317499@main)) (118115749) - Fixed an issue where search in Web Inspector did not find results inside the shadow DOM. ([317500@main](https://commits.webkit.org/317500@main)) (126458322) - Fixed an issue where Web Inspector could crash when selecting a popover matching a nested `@scope` with a bare declaration. ([316987@main](https://commits.webkit.org/316987@main)) (181745000) - Fixed an issue where Web Inspector mapped the `crimson` named color to the wrong RGB value. ([317047@main](https://commits.webkit.org/317047@main)) (182090064) - Fixed an issue where the gradient editor in Web Inspector dropped explicit `0%` color stops and misparsed leading radial color stops. ([317192@main](https://commits.webkit.org/317192@main)) (182172439) - Fixed an issue where autocompleting a vendor-prefixed value in Styles could duplicate the prefix, for example producing `-apple--apple-system`. ([317167@main](https://commits.webkit.org/317167@main)) (182178871) ### WebAssembly #### Resolved Issues - Fixed an issue where `Error` stack traces did not include names for modules instantiated with `WebAssembly.instantiateStreaming`. ([316642@main](https://commits.webkit.org/316642@main)) (181523735) ### WebDriver #### New Features - Added WebDriver support for the Digital Credentials API, including commands to simulate wallet payloads, indefinite waits, and user rejection. ([316435@main](https://commits.webkit.org/316435@main)) (168941907) ### WebRTC #### Resolved Issues - Fixed `OverconstrainedError` to inherit from `DOMException` and expose a `code` attribute per the Media Capture spec. ([316578@main](https://commits.webkit.org/316578@main)) (180728516) --- 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)