Release Notes for Safari Technology Preview 141

Safari Technology Preview Release 141 is now available for download for macOS Big Sur and of macOS Monterey. If you already have Safari Technology Preview installed, you can update in the Software Update pane of System Preferences on macOS.

This release covers WebKit revisions 288438-289213.

Note: Tab Groups do not sync in this release.

Web Inspector

  • Sources Tab
    • Enabled automatic collapsing of blackboxed call frames (r288580)
  • Network Tab
    • Collapsed resource type filter scope bar into a single button to save space (r288469)
    • Changed the Ignore Caches icon to be a button with a label so it’s more visible and immediately understandable (r288533)
    • Moved the Group Media Requests and Preserve Log checkboxes into a single filter icon that shows a contextmenu with those options when clicked to save space (r288470)
  • Graphics Tab
    • Added the display of more pseudo-elements than ::before and ::after (r288623)
  • Console Tab
    • Moved the Preserve Log checkbox into a single filter icon that shows a contextmenu with those options when clicked to save space (r288702)


  • Enabled support for overflow: clip (r288973)
  • Implemented CSS overscroll-behavior for asynchronous scrolling on macOS (r288777)
  • Fixed removal of not yet loaded CSS @import (r288879)
  • Fixed CSS Grid shorthand expansion of initial values (r288544)
  • Fixed scroll-margin-top on inline elements (r288947)


  • Fixed the value not changing for stepUp() and stepDown() with out-of-range values (r289075)
  • Fixed grouping radio buttons with no form owner (r288734)
  • Used min as the default value when min is greater than max for <input type="range"> (r289209)


  • Added support for the WASM branch hinting proposal (r288758, r288761)
  • Added support for the import assertion syntax behind a flag (r288473)
  • Fixed object literal to properly resolve a name clash between an accessor and a constant property (r289166)

Experimental Model Element

  • Allowed disabling interaction (r288728)
  • Fixed mouse interaction flipped in the y-axis (r288610)
  • Fixed <model> to not be draggable on macOS (r288723)

Payment Request

  • Allowed additional payment method specific data to be passed to complete() (r288698)

Web Animations

  • Fixed accelerated transform animations that start with a 1ms delay (r289211)
  • Fixed de-duplication for @keyframes rules to account for animation-composition (r288571)
  • Fixed the ability to redefine @keyframes (r288882)
  • Fixed using logical properties in the transition syntax (r289161)
  • Resolved logical properties when compiling the list of transition properties (r289167)


  • Changed the HTMLMediaElement to dispatch the resize event asynchronously (r289108)
  • Changed to remove customElements when transitioning documents (r288450)
  • Fixed slow, CPU-bound (r288463)
  • Fixed Geolocation API to callback with an error if the document is not fully active (r288707)
  • Fixed ServiceWorkerNavigationPreloader to only be used once (r288949)
  • Implemented AbortSignal.timeout() (r289058)


  • Allowed use of hardware-fixed credentials while using “Syncing Platform Authenticator” (r289059)
  • Added authenticator attachment to PublicKeyCredential (r288622)

Content Security Policy

  • Fixed returned WebAssembly error type when blocked (r288992)
  • Fixed blocking image content in object elements (r288792)
  • Implemented wasm-unsafe-eval (r289022)