Release Notes for Safari Technology Preview 81

Safari Technology Preview Release 81 is now available for download for macOS Mojave and macOS High Sierra. If you already have Safari Technology Preview installed, you can update in the Software Update pane of System Preferences on macOS Mojave and from the Mac App Store’s Updates tab on macOS High Sierra. After updating to macOS Mojave, you may have to reinstall Safari Technology Preview.

This release covers WebKit revisions 244110-244684.

Dark Mode

  • Renamed supported-color-schemes to color-scheme (r244408)
  • Standardized the <meta name="color-scheme"> separator (r244413)


  • Added support for incremental bytecode cache updates (r244143)


  • Allowed the MediaSource API to be enabled via website policy (r244197)
  • Prevented restarting WebRTC stats timer if backend is stopped (r244632)
  • Supported RTCDataChannel blob binaryType (r244196)
  • Added support for parsing FairPlayStreaming PSSH boxes. (r244439)


  • Updated AudioSession route sharing policy (r244223)
  • Fixed layout issues occuring when entering full screen mode (r244545)


  • Added @page margin support (r244202)
  • Fixed synthesized baseline for CSS Grid and CSS Flex (r244213)


  • Removed deprecated Accessibility Object Model events (r244582)


  • Changed requestAnimationFrame to execute before the next frame (r244182)
  • Changed visited link hash to be computed only once (r244642)
  • Fixed link clicks in PDFs to not send referrer headers (r244405)


  • Changed to clear cache storage structures before removing all related files (r244162)
  • Delayed initialization of quota users until the first quota request (r244112)
  • Fixed blob type not getting stored correctly in IndexedDB when IDBObjectStore has autoIncrement and keyPath options (r244436)


  • Changed to Ignore X-Frame-Options header when frame-ancestors CSP directive is present (r244589)
  • Implemented remembering device orientation permission for the duration of the browsing session (r244382)

Web Inspector

  • Added line and column numbers with source location when logging CSP messages to the console (r244563)
  • Added support for drag-and-drop to import files in the Canvas and Audit tabs (r244278)
  • Added support for drag-and-drop to import HAR archives in the Network tab (r244576)
  • Added support to show Worker imported scripts in the Open Quickly dialog even if Web Inspector is opened after the Worker was created (r244363)
  • Changed to prevent starting property selection when pressing the right mouse button in the Styles sidebar (r244616)
  • Changed to show a resource in the Debugger even if an extension script throws a parse error (r244398)
  • Changed to include the number of Network Requests in the Statistics section of the CPU Usage timeline (r244411)
  • Ensured that object previews with Promises don’t add unnecessary catch handlers that prevent rejectionhandled events from being fired in the Console (r244312)
  • Ensured that tracking stops for the CPU Usage Timeline when disconnecting Web Inspector (r244478)
  • Fixed an issue where navigating to a resource sometimes shows a different resource (r244412)
  • Made starting and stopping a recording more consistent and reliable in the Timelines tab (r244195)
  • Provided a more obvious way to return to the overview when viewing imported recordings in the Canvas tab (r244560)
  • Updated to preserve multiple selection in the Elements tab when switching tabs (r244154)
  • Updated to disable special breakpoints when they are deleted in the Sources tab (r244274)


  • Added hooks to make it possible to easily run WPT WebDriver web server by itself (r244492)
  • Fixed JavaScript evaluation failures if a dialog is shown (r244230)
  • Fixed enter fullscreen error handling code (r244236)
  • Fixed the Set Cookie endpoint to correctly set subdomain cookies (r244281)


  • Implemented support for indexed drawing (r244147)
  • Prevented narrowing conversions during Metal function calls on 32-bit platforms (r244235)

Privacy Preserving Ad Click Attribution

  • Added the privacy preserving Ad Click Attribution API as an experimental feature (r244581)