Safari Technology Preview 241: Key Improvements and Fixes

Overview

Apple has released Safari Technology Preview 241, the latest experimental build of its web browser engine. Available for macOS Tahoe and macOS Sequoia, this update introduces several enhancements and bug fixes across accessibility, animations, and CSS. Existing users can upgrade via System Settings → General → Software Update. The build incorporates WebKit changes from revision 309287 to 310186.

Accessibility Upgrades

Resolved Issues

• Speech synthesis cancellation: Calling speechSynthesis.cancel() no longer removes utterances queued by subsequent speechSynthesis.speak() calls. (309349)
• MathML bounding boxes: Incorrect bounding boxes for MathML table rows and cells have been corrected. (309640)
• Combobox focus forwarding: Comboboxes now properly forward focus to their aria-activedescendant, enabling assistive technologies to interact with list items. (309641)
• ARIA-owns support: The aria-owns attribute is now respected when computing accessible names from element content. (310020)

Animation Fixes

Resolved Issues

• Viewport-based units in animation-fill-mode: The animation-fill-mode property now correctly applies viewport-based units after the viewport is resized. (310007)

CSS Enhancements and Corrections

New Features

• Stretch keyword for box sizing: Added support for the stretch keyword in box sizing properties (box-sizing). (309405)
• Scroll anchoring: Stable support for CSS scroll anchoring is now included. (310113)

Resolved Issues

• Line separator rendering: U+2028 LINE SEPARATOR is now rendered as a forced line break per the CSS specification. (309701)
• Outline offset inflation: The outline-offset property is no longer inflated when using outline: auto on macOS. (309812)
• Font-family serialization: Serialization now preserves quotes around family names that match CSS-wide keywords or generic families. (309959)
• Unnecessary font downloads: Fonts are no longer downloaded when no characters in the document fall within their unicode-range. (309360)
• Flex item with percentage-height image: A flex item containing a percentage-height image now shrinks correctly. (309544)
• View Transition snapshots: Snapshots previously stored in sRGB now render correctly with non-sRGB colors. (310012)
• Contain:layout performance: The contain: layout property no longer causes significantly slower forced layouts when all siblings create their own formatting context. (310173)
• Ruby underlines: Underlines are no longer split when a ruby base expands due to long ruby text. (309356)
• Color-scheme repaint: Changing color-scheme now repaints the background of composited iframes. (309567)
• Popover nested children: Nested children of a popover element now render correctly when using position: absolute. (310019)
• Color:initial in dark mode: color: initial now resolves to the correct color in dark appearance mode. (309430)
• Display:contents and anchor-scope: An element with display: contents now establishes an anchor scope when using anchor-scope. (309946)
• Media query regression: A regression where media queries could fail to resolve correctly has been fixed. (310173)

For more details, refer to the overview and specific sections above. This release continues Apple’s commitment to refining WebKit for developers and users alike.