Release Notes for Safari Technology Preview 154

Safari Technology Preview Release 154 is now available for download for macOS Monterey 12.3 or later and macOS Ventura beta. If you already have Safari Technology Preview installed, you can update in the Software Update pane of System Preferences on macOS Monterey, or System Settings under General → Software Update on macOS Ventura.

This release includes WebKit changes between: 253848@main…254351@main

Note: Shared Tab Groups and syncing for Tab Groups, Website Settings, and Web Extensions are not enabled in this release.

Web Inspector

  • Sources Tab
  • Elements Tab
    • Added “Scroll” labels in the element tree for scrollable elements (254061@main)
    • Added warnings in the Font details sidebar for synthesized boldness or obliqueness (254188@main)
    • Fixed DOM Tree to update when a top-level item in the DOM tree is added or removed (254062@main)
    • Prevented showing the Target in the Event badge popover (254018@main)
  • Timelines Tab
    • Fixed selecting timeline records from a coalesced record bar selecting the first record in the group, not the record nearest the cursor. (254056@main)
  • Settings
    • Added a setting to control whether nodes that are not rendered are de-emphasized (254022@main)



  • Fixed ShadowRealm test262 failures (253977@main)
  • Finished to and from methods for Temporal.PlainDate[Time] (Behind the --useTemporal flag) (253876@main)
  • Optimized Proxy [[Get]] operations (254092@main)
  • Optimized String#replace(String, String) (254156@main)
  • Optimizde String#replace with constant String via Boyer-Moore-Horspool search algorithm (254342@main)


  • Fixed incorrect bidi visual direction after forced line break (253872@main)
  • Fixed <div> with border-radius not getting repainted correctly when the bounds change (254041@main)
  • Fixed border-radius clipping of composited layers (254253@main)
  • Fixed updating transforms on table sections (254351@main)

Reporting API

  • Added support for generateTestReport in WebDriver (254122@main)
  • Hooked up to Content-Security-Policy 'report-to' directive (253966@main)
  • Refactored network send logic for Report-related code (254208@main)


  • Added support for COOP navigation violation reporting (254291@main)
  • Added support for ElementInternals.role, ariaLabel, and ariaRoleDescription (254278@main)
  • Added support for PermissionStatus.onchange (254193@main)
  • Added support for InputEvent.isComposing (254131@main)
  • Added ReferrerPolicy to the PolicyContainer (254003@main)
  • Added generation of IndexedDB object serializers (254196@main)
  • Enabled Scroll To Text Fragment by default (253855@main)
  • Enabled SKAttributionEnabled by default (254328@main)
  • Changed to not parse or scroll to text fragments in iframe URLs (254073@main)
  • Fixed memory usage scaling for Compression Streams to handle out-of-memory conditions (253930@main)
  • Fixed deleting a button element leaving the style inside the button element (254285@main)
  • Fixed matching fancy quotes and apostrophes for Scroll To Text Fragment fragments (254275@main)
  • Fixed link elements to be able to fire more than one load or error event (254290@main)
  • Fixed String.prototype.includes incorrectly returning false when the string is empty and the position is past end of string (254319@main)
  • Fixed opening the share sheet to not clear the text selection (254136@main)
  • Fixed <canvas> ConicGradient angle to start at the x-axis, not at the top (254038@main)
  • Fixed X-Frame-Options HTTP headers with an empty value being incorrectly ignored (254245@main)
  • Stopped painting a border for images with loading="lazy" before it loaded (253960@main)


  • Implemented WebVTT-based audio descriptions with text-to-speech (253931@main, 254266@main)
  • Implemented the ARIA 1.3 mark role, which provides parity with the <mark> tag (254008@main)


  • Fixed AudioWorklet scripts to inherit their owner document’s referrer policy (254306@main)
  • Fixed canPlayType for WebM VP8 on older Macs without VP9 (254013@main)
  • Fixed WebM files that fail to play (254219@main)
  • Fixed WebVTT styles not getting applied with in-band tracks (254109@main)

Intelligent Tracking Prevention

  • Updated to wait longer before deleting website data for domains where a user interacted with a Web Push notification (254048@main)