Apple Releases Safari Technology Preview 248 – Brings Bug Fixes and Performance Improvements
Apple hasreleasedSafari Technology Preview 249, the latest version of its developer preview web browser. The preview version of Apple’s popular browser offers developers and other interested users the ability. . .
Apple hasreleasedSafari Technology Preview 249, the latest version of its developer preview web browser. The preview version of Apple’s popular browser offers developers and other interested users the ability to try out features that may or may not, debut in future public release versions of Safari. Safari Technology Preview 249 includes fixes and updates for Accessibility, Animations, CSS, Editing, Forms, HTML, JavaScript, Media, Rendering, Spatial Web, Web API, Web Audio, Web Inspector, WebAssembly, WebDriver, and WebRTC. The current Safari Technology Preview release is compatible with machines running macOS 26 Tahoe and macOS 27 Golden Gate, the newest version of macOS that will launch later this year. OverviewSafari Technology PreviewRelease 249 is nowavailable for downloadfor 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. AccessibilityResolved IssuesFixed an issue where anaria-labelledbyrelation was not built when its target element was inserted viainnerHTML. (316913@main) (179677418)Fixed an issue where VoiceOver was silent during character navigation inside a local iframe. (317264@main) (182229891)Fixed an issue where web content somtimes appeared empty to assistive technology after navigation. (317449@main) (182544199)AnimationsResolved IssuesFixed an issue where callingplay()on a finite scroll-driven animation timeline did not reset its start time to the current time. (316745@main) (181712713)Fixed an issue whereanimation-timelinedid not use the last matching timeline when it matched multiple timelines. (317330@main) (182405676)Fixed an issue whereanimation-timelinecould match a timeline outside the nearesttimeline-scopeelement with that name. (317376@main) (182417407)CSSNew FeaturesAdded support for theattr()function. (316672@main) (173992627)Added support foroutline-offset: inset. (316677@main) (180547604)Added support for the@functioncustom functions rule. (316671@main) (181625123)Added preview support for thewrap-insideproperty. (317182@main) (181751564)Added support for theif()function. (316813@main) (181806268)Added support forcalc-mix(). (316847@main) (181839626)Added support forjustify-selfon block-level boxes. (317212@main) (181926245)Added preview support fortext-decoration-inset. (317230@main) (182019037)Added preview support for thecontentproperty on the::markerpseudo-element. (317211@main) (182066124)Resolved IssuesFixed an issue where settingview-transition-namedynamically did not create a stacking context. (317310@main) (178316558)Fixed an issue where CSS Grid items with a computed preferred size that behaves asautodid not correctly compute their minimum content contribution. (316697@main) (181146154)Fixed an issue where visually overflowing content in a CSS Grid item was not painted. (316668@main) (181277780)Fixedanchor-centerin vertical writing modes not being scroll-adjusted along the block axis. (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) (181485387)Fixed an issue where CSS Grid did not correctly increase track sizes to accommodate items spanning flexible tracks. (317426@main) (181635324)Fixed an issue where stretch alignment did not trigger stretch sizing for CSS Grid items. (316949@main) (181750071)Fixed an issue where CSS Grid items could retain stale block sizes after a subsequent layout. (317166@main) (182144347)Fixed an issue whereclip-pathshapes could render with incorrect arcs. (317397@main) (182443333)Fixed an issue where::highlight()and::target-textignoredtext-underline-offset. (317440@main) (182466757)Fixed an issue where::highlight()decoration replaced the originating element’s decoration instead of layering over it. (317439@main) (182523249)EditingResolved IssuesFixed an issue that disallowed font names that were not a valid CSS identifiers. (316948@main) (51409819)Fixed the Edit menu’s Copy item being incorrectly enabled when there was no selection in the web page. (316571@main) (176061974)FormsResolved IssuesFixed an issue where thedatalistpopup menu was presented in the wrong place on a screen to the left of the main screen. (316965@main) (181967418)HTMLNew FeaturesAdded support forpopover=hint. (317402@main) (129495028)JavaScriptNew FeaturesAdded support for theTemporalobject. (316742@main) (181723535)MathMLResolved IssuesFixed an issue where U+2016 (DOUBLE VERTICAL LINE) was missing the symmetric property in the MathML operator dictionary. (316867@main) (179558196)MediaResolved IssuesFixed 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) (182001231)RenderingNew FeaturesAdded support for dark mode in the XML document viewer. (316832@main) (122234600)Resolved IssuesFixed an issue wherebox-shadowrendering broke when the page was zoomed. (317080@main) (169167365)ScrollingResolved IssuesFixed an issue where re-snapping did not select the snap area aligned in both axes when multiple targets were aligned. (317294@main) (182285397)Fixed an issue wherescroll-snap-alignwas not respected when scrolling to an anchor or callingscrollIntoView(). (317495@main) (182544180)Spatial WebResolved IssuesFixed 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) (180966321)Fixed an issue where the background color ofHTMLModelElementdid not match spec for non-opaque colors. (316788@main) (181641249)Web APINew FeaturesAdded support for subgroups in WebGPU. (317145@main) (154874391)Added support for close watchers, including theclosedbyattribute fordialogelements. (316680@main) (180105698)Resolved IssuesFixed an issue where a user gesture authorization token was not properly verified for Digital Credentials requests. (317228@main) (174908839)FixedDOMMatrixandIntersectionObservercorrectly enforcing absolute-length unit requirements when parsing values. (316532@main) (181453666)Fixed an issue where Scroll To Text Fragment directives could run outsidetext/htmlandtext/plaindocuments. (316976@main) (181763736)Fixed an issue wherereplaceChildren()could not replace a document’s children. (316909@main) (181921026)Web AudioResolved IssuesFixed Web AudioPannerNodeorientation-only changes not updating the directional cone gain. (316541@main) (181413407)Web InspectorNew FeaturesAdded support for the range mappings proposal in source maps. (316748@main) (178564308)Added per-elementLayout Invalidatedevents in Web Inspector to reflect the number of elements affected by a layout invalidation. (317302@main) (181243589)Resolved IssuesFixed an issue where everyelement showed a Scroll badge in the Elements tab. (316773@main) (101661656)Fixed an issue where search results did not select the corresponding source code line for fetched JSON. (317499@main) (118115749)Fixed an issue where search in Web Inspector did not find results inside the shadow DOM. (317500@main) (126458322)Fixed an issue where Web Inspector could crash when selecting a popover matching a nested@scopewith a bare declaration. (316987@main) (181745000)Fixed an issue where Web Inspector mapped thecrimsonnamed color to the wrong RGB value. (317047@main) (182090064)Fixed an issue where the gradient editor in Web Inspector dropped explicit0%color stops and misparsed leading radial color stops. (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) (182178871)WebAssemblyResolved IssuesFixed an issue whereErrorstack traces did not include names for modules instantiated withWebAssembly. instantiateStreaming. (316642@main) (181523735)WebDriverNew FeaturesAdded WebDriver support for the Digital Credentials API, including commands to simulate wallet payloads, indefinite waits, and user rejection. (316435@main) (168941907)WebRTCResolved IssuesFixedOverconstrainedErrorto inherit fromDOMExceptionand expose acodeattribute per the Media Capture spec. (316578@main) (180728516)The update is available through the Software Update mechanism in System Preferences or System Settings to anyone who hasdownloaded the browserfrom Apple’s website. Next UpApple is Developing an All-New Operating System for Smart Home Hub