Safari Technology Preview 242: Key Updates and Improvements

Apple has released Safari Technology Preview 242, now available for download on macOS Tahoe and macOS Sequoia. If you already have the preview installed, you can update via System Settings → General → Software Update. This build includes WebKit changes between revisions 310187 and 310599, bringing a host of refinements and new features for web developers and early adopters.

Accessibility Enhancements

The latest version addresses two important accessibility issues:

• VoiceOver no longer reads text within images that carry the role="presentation" attribute, ensuring that decorative images are properly ignored.
• macOS accessibility support for customizable <select> elements using appearance: base-select has been fixed, improving the experience for users relying on screen readers.

CSS Improvements

New Features

• Support for the CSS attr() function from CSS Values Level 5 has been added, giving developers more powerful ways to use attribute values in styles.
• The oblique-only value for font-synthesis-style (as defined in CSS Fonts Level 4) is now supported, enabling finer control over font style synthesis.

Resolved Issues

• A bug where @media (prefers-color-scheme: dark) inside an iframe did not match when the iframe's color-scheme was set to dark has been fixed.
• position-try-order now correctly interprets logical axis values using the containing block's writing mode instead of the element's own writing mode.
• Percent-height replaced elements no longer compute stale preferred widths in shrink-to-fit containers.
• The table cell nowrap minimum width calculation quirk is no longer applied outside of quirks mode.
• Checkbox outlines are now aligned properly, addressing a visual glitch.
• Anchor-positioned elements anchored to children of sticky-positioned boxes now stick correctly.
• Pseudo-elements are sorted correctly when sorting anchor elements by tree order.
• Ligatures no longer cause non-zero layout width for text with font-size: 0.
• The :in-range and :out-of-range pseudo-classes now update correctly when the readonly attribute changes.
• view-timeline-inset serialization no longer fails to coalesce identical values.

Forms

A fix has been applied to <select multiple> elements: the onchange event now fires reliably even when the mouse button is released far outside the element.

HTML Updates

New Features

• Support for the closedby attribute on <dialog> elements has been added, allowing developers to control how dialogs are dismissed.

Resolved Issues

• The HTML parser fast path now correctly processes escaped attribute values longer than one character.
• Nested <li> elements are now correctly detected in the parser fast path.
• The fast path now uses the adjusted current node for MathML and SVG integration point checks.

Images

A resolution was applied to an issue involving the insertion of images with a srcset attribute into the document. Details of the fix are available in the full release notes.

We encourage all web developers to download Safari Technology Preview 242 and test these changes in their projects. As always, your feedback helps shape the future of WebKit and the web platform.