Release Notes for Safari Technology Preview 26

Safari Technology Preview Release 26 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 213542-213822.



  • Added support for history.scrollRestoration (r213590)
  • Aligned Document.elementFromPoint() with the CSSOM specification (r213646)
  • Changed the parameter to input.setCustomValidity() to not be nullable (r213606)
  • Fixed transitions and animations of background-position with right-relative and bottom-relative values (r213603)
  • Fixed an issue where WebSQL directories were not removed when removing website data (r213547)
  • Made the XMLHttpRequest method setRequestHeader() use “,” (including a space) as the separator (r213766)
  • Prevented displaying the label of an <option> element in quirks mode (r213542)
  • Prevented extra downloads of preloaded CSS (r213672)
  • Dropped support for non-standard document.all.tags() (r213619)


  • Implemented stroke-width CSS property (r213634)


  • Enabled asynchronous image decoding for large images (r213764, r213563)
  • Fixed memory estimate for layers supporting subpixel-antialised text (r213767)
  • Fixed columns getting clipped horizontally in CSS Multicolumn (r213593)

Web Inspector

  • Added DOM breakpoints for pausing on node and subtree modifications (r213626)
  • Added XHR breakpoints for pausing on requests by URL (r213691)
  • Added a “Create Breakpoint” context menu item for linked source locations (r213617)
  • Added settings for controlling Styles sidebar intelligence (r213635)
  • Added cache source information (Memory Cache or Disk Cache) in the Network tab (r213621)
  • Added protocol, remote address, priority, and connection ID in the Network tab (r213682)
  • Added individual messages to the content pane for a WebSocket (r213666)
  • Fixed an issue where the DOM tree is broken if an element has a debounce attribute (r213565)
  • Fixed an issue in the Resources tab navigation bar allowing the same file from a contextual menu item to be saved more than once (r213738)
  • Improved the layout of the compositing reasons in the Layers sidebar popover (r213739)


  • Fixed an issue where automation commands hang making it impossible to navigate back or forward (r213790)


  • Implemented ECDH ImportKey and ExportKey operations (r213560)