Safari Technology Preview Release 228 is now available for download 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: 299100@main…299754@main.

Accessibility

New Features

• Added support for auto-expanding details and hidden=”until-found” elements for text searches done via assistive technologies. (299649@main) (159913471)

Resolved Issues

• Fixed an issue where VoiceOver reports the wrong radio count with a dynamically inserted radio option. (299585@main) (159221583)
• Fixed exposing content within dynamically expanded details elements in the accessibility tree. (299601@main) (159291226)

CSS

New Features

• Added support for :scope when the scoping root is :visited. (299560@main) (157588890)
• Added support for using color-mix() without a color space, defaulting to oklab. (299440@main) (159039709)
• Added support for display-p3-linear colors in CSS. (299381@main) (159579630)

Resolved Issues

• Fixed -webkit-user-select: none disabling find-in-page in Safari. (299624@main) (8081660)
• Fixed anchor position to only generate position options on base style. (299135@main) (158900076)
• Fixed out-of-flow box with no sibling ignoring align-content. (299107@main) (159097576)
• Fixed performance of :has(> .changed) .subject selectors. (299162@main) (159173631)
• Fixed handling of the ::first-line pseudo-element when floats prevent the initial line from containing inline content, ensuring correct styling is applied to the actual first formatted line. (299402@main) (159613287)

DOM

Resolved Issues

• Fixed an issue where command-clicking to open a link in a new tab navigates the current tab. (299537@main) (57216935)

Editing

Resolved Issues

• Fixed jumbled text when copy/pasting bidirectional text starting with left-to-right. (299176@main) (152236717)

Forms

Resolved Issues

• Fixed <select> element with long <option> text causing horizontal scrolling in grid or flex containers. (299631@main) (141633685)
• Fixed checkboxes and radio buttons missing borders in the filled state when “Increased Contrast” is enabled on macOS. (299269@main) (159226308)
• Fixed switch controls that may be sized incorrectly due to incorrect margins. (299543@main) (159729284)

JavaScript

New Features

• Added support for Wasm Memory buffer APIs. (299236@main) (159305098)
• Added support for Wasm JS String Builtins. (299455@main) (159679027)

Resolved Issues

• Fixed non-standard new Date(2024-12-3) yielding to an “Invalid Date” error. (299182@main) (141044926)
• Fixed poor error messages for destructing null or undefined values. (299244@main) (159340067)

Media

Resolved Issues

• Fixed western Arabic numbers being displayed in the video viewer instead of eastern Arabic numbers. (299348@main) (141281469)
• Fixed handling of null media accessibility caption profile. (299204@main) (159134245)
• Fixed hiding and resuming a webm video that sometimes causes a decoding error. (299366@main) (159508950)

PDF

Resolved Issues

• Fixed VoiceOver not recognizing the password form. (299180@main) (155907450)

Rendering

Resolved Issues

• Fixed list markers overlapping text in certain situations. (299671@main) (157054277)
• Fixed string search freezing when subject has large number (>1000). (292919@main) (159129919)
• Fixed position-visibility: anchors-visible visibility heuristic in certain situations. (299554@main) (159790886)
• Fixed buttons with box shadow being broken. (299603@main) (159888287)

SVG

Resolved Issues

• Fixed an issue where a dynamic change in a CSS property of an SVG element does not get reflected in the instances of the SVGElement. (299112@main) (98577657)
• Fixed an issue where <view> element was not applied to the root element. (299459@main) (159705519)

Service Worker

Resolved Issues

• Fixed an issue where service worker downloads are not being saved to Downloads folder. (299564@main) (154501503)

Web API

Resolved Issues

• Fixed preventing the javascript: protocol in navigation.navigate(). (299235@main) (158867866)
• Fixed an issue where click and auxclick event targeting does not follow pointer capture target override. (299567@main) (159477637)

Web Extensions

Resolved Issues

• Fixed an issue that caused the web page to crash when navigating to certain URLs with an extension enabled. (299173@main) (158180410)

Web Inspector

Resolved Issues

• Fixed an issue where accepting a completion suggestion for a shorthand property value would malform the combined value. (299157@main) (159107788)
• Fixed issue where searching on certain text fails to find matches. (299541@main) (159272725)

WebGPU

Resolved Issues

• Fixed incorrect handling of some PNG pixel formats in WebGPU. (299404@main) (158797747)

WebRTC

New Features

• Added encrypted field to RTCRtpHeaderExtensionParameters. (299356@main) (159279401)

Resolved Issues

• Fixed camera indicator staying enabled even after ending a meeting/access to camera. (299161@main) (152962650)