Safari Technology Preview 240: Key Updates and Bug Fixes
The latest iteration of Apple's experimental browser, Safari Technology Preview 240, is now available for download. This release is compatible with macOS Tahoe and macOS Sequoia. Existing users can update via System Settings → General → Software Update. It incorporates WebKit changes from revision 308418 to 309286, bringing a host of improvements across CSS, editing, forms, HTML, and media handling.
CSS Enhancements and Fixes
New CSS Feature: revert-rule Keyword
Developers can now use the revert-rule CSS keyword. This keyword effectively rolls back the cascade, making the browser behave as if the current style rule had never been applied. It provides finer control over style inheritance and conflict resolution. (308733@main)
Resolved CSS Issues
- Custom scrollbar cutting: On macOS, custom CSS scrollbars could appear truncated due to an incorrectly sized scrollbar corner rect. This has been fixed. (309119@main)
- Hanging punctuation improvements: The
hanging-punctuationproperty now correctly supports the apostrophe (U+0027) and quotation mark (U+0022) as hangable characters. Additionally, the ideographic space (U+3000) is now permitted to hang when used as the first value. (308597@main, 308605@main)
Editing Bug Fixes
Font Picker Stability
An issue where the Font Picker style selection became unresponsive after switching fonts while editing multiple lines of text has been resolved. (308562@main)
Emoji Preservation in Copy-Paste
Emoji images are now correctly retained when copying and pasting content between different websites. Previously, they could be lost during the transfer. (309176@main)
Selection Jumping with Absolute Positioning
Text selection no longer jumps unexpectedly when selecting absolutely-positioned content inside an element with user-select: none. (308451@main)
Forms Improvement
Keyboard Focus Tabbing
Fixed a bug where keyboard tabbing position was lost when a focused button became disabled. Focus no longer jumps to the top of the page, preserving the user's expected navigation flow. (308991@main)
HTML Parsing Corrections
Viewport Meta Parsing
The viewport <meta> parsing now correctly treats the form feed character as ASCII whitespace, aligning with the HTML specification. (309044@main)
Margin Attribute Parsing
Pixel-length margin attributes on <body>, <iframe>, and <frame> elements are now parsed correctly, fixing an earlier inconsistency. (308526@main)
Media and Video Enhancements
Audio and Video Decoding
- WebM audio channels: Decoding WebM audio files with more than two channels no longer fails. (308749@main)
- VP8 in WebM detection:
MediaCapabilities.decodingInfo()now correctly reports VP8 in WebM as supported. (308789@main) - Opus in MP4: MP4 files containing Opus audio tracks can now be decoded using
decodeAudioData. (309140@main)
Playback and Interaction
- Live Text on fullscreen video: Live Text selection is now available on paused fullscreen videos. (308498@main)
- FairPlay-protected VP9: Content protected by FairPlay that uses VP9 codec can now play via
MediaSource. (308622@main) - Autoplay and text tracks: Autoplay will no longer proceed before default text tracks finish loading, ensuring captions or subtitles are ready. (308796@main)
- currentTime getter: The
currentTimegetter now returnsdefaultPlaybackStartPositionwhen no media player exists. (308654@main) - timeupdate event: HTMLMediaElement now fires a
timeupdateevent when resetting playback position during media load, as required by the specification. (308695@main) - Preload attribute: Addressed an issue where the media player preload attribute did not function correctly. (309197@main)
For a complete list of changes, visit the official WebKit commit log. Safari Technology Preview continues to offer a glimpse into the future of web standards on Apple platforms.