Apple’s Safari Technology Preview 241 Overhauls Accessibility and CSS Rendering with Critical Fixes

Breaking: Safari Technology Preview 241 Now Available

Apple has released Safari Technology Preview 241 for macOS Tahoe and macOS Sequoia, bringing a wave of critical fixes and new features. The update is available immediately for download or via System Settings under General → Software Update.

The release targets long-standing accessibility issues, including a fix for speech synthesis and combobox focus failures. It also introduces stable CSS scroll anchoring and the stretch keyword for box sizing.

“This release represents a significant step forward in ensuring assistive technologies work seamlessly with modern web apps,” said a WebKit engineer. “The combobox fix alone will unlock better navigation for millions of users relying on screen readers.”

Key Fixes and Features

Accessibility

• Speech synthesis: Fixed speechSynthesis.cancel() removing utterances queued by subsequent speak() calls.
• MathML layout: Corrected bounding boxes for table rows and cells.
• Combobox focus: Resolved a bug where comboboxes failed to forward focus to aria-activedescendant, blocking assistive tech from list items.
• Aria-owns naming: Fixed aria-owns not being used in accessible name computation.

Animations

• Viewport units: Fixed animation-fill-mode not correctly applying viewport-based units after window resize.

CSS Enhancements

• Box sizing: Added support for the stretch keyword, enabling more flexible element sizing.
• Scroll anchoring: Stable support now available, preventing page jumps when content loads.
• Line separator: U+2028 LINE SEPARATOR now renders as a forced line break per specification.
• Outline offset: Fixed inflation on macOS for outline: auto.
• Font-family serialization: Preserves quotes around family names that match CSS-wide keywords.
• Unicode-range: Prevents unnecessary font downloads for characters outside document’s range.
• Flex item shrink: Percentage-height images inside flex items now shrink correctly.
• View Transitions: Snapshots no longer incorrectly stored in sRGB, fixing rendering with non-sRGB colors.
• Performance: contain: layout no longer causes severe slowdowns when all siblings create formatting contexts.
• Ruby underlines: Underlines no longer split when ruby base is expanded by long text.
• Color-scheme repaint: Changing color-scheme now repaints composited iframe backgrounds.
• Popover children: Nested children of popover elements now render correctly with position: absolute.
• Color initial: Fixed color: initial resolving to wrong color in dark mode.
• Anchor scope: Elements with display: contents now establish anchor scope correctly.
• Media queries: A regression that caused media queries to fail under certain conditions has been resolved.

Background: What is Safari Technology Preview?

Safari Technology Preview is Apple’s experimental browser aimed at developers and early adopters. It provides a preview of upcoming WebKit technologies and allows testing of new features before they land in stable Safari releases.

Version 241 includes changes from WebKit commits 309287 through 310186, spanning accessibility, CSS, animations, and rendering.

What This Means

For web developers, the CSS scroll anchoring and stretch keyword offer more predictable layouts without hacky workarounds. The performance fix for contain: layout will make complex single-page apps snappier.

For users with disabilities, the combobox focus and speech synthesis fixes are game-changers. Assistive technologies will now correctly interact with ARIA widgets, making web forms and applications far more usable.

Apple urges developers to install the preview immediately and report any regressions. The stabilized features are expected to roll into a future Safari release.

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