Safari Technology Preview 242: Key Improvements and Fixes
Apple has released Safari Technology Preview 242, bringing a host of refinements and new capabilities for web developers and testers. This update is available for macOS Tahoe and macOS Sequoia, either as a fresh download or via System Settings > General > Software Update for existing users. It incorporates WebKit changes from revision 310187 to 310599. Below, we answer the most pressing questions about what this release includes, from accessibility enhancements to CSS and HTML fixes.
What are the main accessibility fixes in Safari Technology Preview 242?
This release addresses two key accessibility issues. First, VoiceOver no longer reads text inside images that have a role="presentation" attribute, ensuring screen readers ignore purely decorative content. Second, macOS accessibility support is improved for customizable <select> elements that use appearance: base-select. This means developers can now style select menus without breaking keyboard navigation or screen reader functionality. These changes help create more inclusive web experiences, particularly for users who rely on assistive technologies like VoiceOver.
What new CSS features does Safari Technology Preview 242 include?
Two notable CSS features debut in this update. The attr() function from CSS Values Level 5 is now supported, allowing developers to retrieve attribute values directly in CSS, which reduces reliance on JavaScript for dynamic styling. Additionally, the oblique-only value is now available for font-synthesis-style as defined in CSS Fonts Level 4, giving finer control over font style synthesis. These additions align Safari with modern CSS specifications, enabling more expressive and efficient stylesheets.
Which CSS bugs were fixed in this release?
Several CSS issues were resolved to improve rendering consistency. The @media (prefers-color-scheme: dark) query now works correctly inside iframes with a color-scheme: dark setting. The position-try-order property now interprets logical axis values using the containing block’s writing mode instead of the element’s own. 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 quirks mode. Checkbox outlines appear properly aligned. Anchor-positioned elements now stick correctly when anchored to children of sticky boxes. Pseudo-elements sort correctly with anchor elements by tree order. Ligatures no longer cause non-zero layout width for font-size: 0. The :in-range and :out-of-range pseudo-classes update properly when the readonly attribute changes. Finally, view-timeline-inset serialization correctly coalesces identical values.
What improvements were made to forms and HTML parsing?
For forms, a bug in <select multiple> was fixed where the onchange event did not always fire when releasing the mouse button far outside the element. This ensures consistent behavior for multi-select menus. In HTML parsing, three fixes were applied to the fast path: escaped attribute values longer than one character are now correctly processed, nested <li> elements are properly detected, and the adjusted current node is used for MathML and SVG integration point checks. These changes improve rendering accuracy for complex HTML documents.
What new feature was added for dialog elements?
The closedby attribute is now supported on <dialog> elements. This attribute controls how a dialog can be closed by the user. For example, setting closedby="any" allows closing with Escape key or clicking outside, while closedby="none" prevents those interactions. This gives developers more precise control over dialog behavior, enhancing user experience for modals and popovers.
What image-related issue was resolved?
An issue was fixed where inserting an image with a srcset attribute into the document could cause rendering problems. While the release notes do not specify the exact symptom, this fix ensures that responsive images using srcset load and display correctly. This is important for websites that serve different image resolutions based on device capabilities.
How can I install or update to Safari Technology Preview 242?
If you do not have Safari Technology Preview installed, download the latest version from Apple’s developer website for macOS Tahoe or macOS Sequoia. If you already have it, open System Settings, navigate to General > Software Update, and follow the prompts to update. The update includes all the WebKit changes mentioned above. After installation, restart Safari to apply the new features and fixes.