Release Notes for Safari Technology Preview 22

Safari Technology Preview Release 22 is now available for download for macOS Sierra. If you already have Safari Technology Preview installed, you can update from the Mac App Store’s Updates tab. This release covers WebKit revisions 210274-210845.


  • Fixed an error when calling an async arrow function which is in a class’s member function (r210558)
  • Improved the speed of Array.prototype.slice in DFG/FTL JITs (r210695)


  • Implemented scroll-snap-type:proximity scroll snapping (r210560)
  • Fixed updating :active and :hover states across Shadow DOM slots (r210564)
  • Fixed a CSS Grid issue with very big values for grid lines (r210320)
  • Implemented baseline positioning for grid containers (r210792)
  • Made the CSS Grid sizing data persistent through layouts (r210669)
  • Fixed overflow:scroll scroll position getting restored on back navigation (r210329)

Form Validation

  • Fixed the validation message to use singular form of “character” when maxLength value is 1 (r210447)
  • Truncated lengthy validation messages with an ellipsis (r210425)
  • Aligned email validation with the latest HTML specification (r210361)

Web Inspector

  • Added “Persist Logs on Navigation” to Settings tab (r210793)
  • Added UI zoom level to the Settings tab (r210788)
  • Added Command-, (⌘,) keyboard shortcut to open Settings tab (r210772)
  • Fixed showing application cache details in the Storage tab (r210311)
  • Improved the cubic-bezier editor for invalid inputs in component fields (r210674)
  • Fixed an issue clearing pseudo classes toggled on in the Styles sidebar when Web Inspector is closed (r210316)
  • Fixed resources disappearing from the network tab when an iframe gets removed (r210759)
  • Fixed restoring Settings tab when reopening Web Inspector (r210764)
  • Improved the layout of the spring function editor with left-aligned labels and slider tracks (r210618)


  • Provided more detailed role descriptions for many new HTML5 input types (r210295)
  • Aligned the innerText setter with the HTML specification (r210767)
  • Fixed an issue changing the modified timestamp for a given gamepad when it is updated (r210827)
  • Changed pointer lock to release when the page state is reset for any reason, not just when the process exits (r210281)
  • Fixed editing of nested RTL-to-LTR content (r210831)
  • Support iterating over URLSearchParams objects (r210593)
  • Changed the first parameter of Event.initEvent() to be mandatory (r210559)


  • Added support for MediaKeys.generateRequest() (r210555)
  • Added protection against the MediaPlayer being destroyed in the middle of a load() (r210747)


  • Fixed an issue that caused the highlighting of text using the Yoon Gothic webfont to reflow (r210456)
  • Fixed reordering text inside a blockquote when un-indenting the text (r210524)


  • Volume-separated file URLs: disallowed a file URL on one volume from loading a file on another volume in macOS 10.12.4 or later (r210571)
Note Safari WebDriver is broken in this release. We expect this will be fixed in release 23.