Release Notes for Safari Technology Preview 89

Safari Technology Preview Release 89 is now available for download for macOS Mojave and the macOS Catalina beta. 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 247433-248024.


  • Implemented nullish coalescing with the ?? operator for ESNext (r247819)


  • Added referrerpolicy attribute support for <script> elements (r247509)
  • Changed window.openDatabase to be overridable (r247434)
  • Fixed an IndexedDB error where the starting version change transaction may be neglected (r247649)
  • Fixed the ability to unbold selected text when the system font is used (r247439)
  • Made storing cross-origin top-level prefetches in HTTP cache optional (r247860)
  • Moving right by word boundary right before an object element followed by a <br> element hangs (r247881)
  • Removed support for beforeload on link=prefetch (r247481)


  • Fixed Daring Fireball long press highlights that were unnecessarily inflated due to false illegibility (r247792)
  • Fixed contextual menu actions for YouTube videos (r247901)


  • Exposed the aria-label attribute for <video> elements (r247891)


  • Enabled a WebRTC debug mode without encryption (r247438)
  • Fixed support for FLAC-in-MP4 (r247934)

Web Inspector

  • Added support for console.screenshot with detached (not in main DOM tree) <img> and <picture> elements (r247814)
  • Added support for console.screenshot with ImageData and ImageBitmap (r247812)
  • Added a “Show Grid” navigation item for the Images collection in the Resources tab (r248004)
  • Added an indicator/separator around items in the Images collection in the Resources tab (r248019)
  • Add special case for about:blank resources to show “Resource has no content” message (r247747)
  • Fixed display of application/xml content for XHR requests (r247533)
  • Fixed issues toggling multiple breakpoints when they’re collapsed into one line (r247639)
  • Fixed Command-X (⌘X) to cut selected properties in the Styles sidebar (r247760)
  • Made the Changes panel in the Elements Tab render with LTR text direction (r247492)


  • Implemented errors for GPURenderPipeline creation (r247764)
  • Added descriptive error messages in WHLSL (r247834)
  • Changed checker to setError() when a property access node can’t commit its base type in WHLSL (r247676)
  • Changed to return the zero-value enum in the enum-from-integer constructor when the integer is not a valid enum value in WHLSL (r247675)
  • Made enums work in WHLSL (r247666)
  • Updated matrix memory layout to match HLSL by laying out columns linearly in WHLSL (r247468)