Safari Technology Preview 31 Released for macOS Sierra

Safari Technical Preview

Safari Technology Preview 31 has been released to macOS Sierra. Safari Technology Preview is an experimental version of Safari wherein Apple tests Webkit features and improvements before pushing them to the public Safari browser. Think of it as beta testing, similar to how Apple has beta releases of iOS and macOS before releasing them to the public.

The new release fixes bugs, adds support for more attributes and elements, and patches a security flaw.

Safari Technical Preview

Full Release Notes for Safari Technology Preview 31


  • Added media and type attribute support for <link rel=”preload”> (r217247)
  • Added support for DOMMatrix and DOMMatrixReadOnly (r216959)
  • Fixed getElementById to return the correct element when a matching element is removed during beforeload event (r216978)
  • Fixed skipping <slot> children when collecting content for innerText (r216966)


Fixed a syntax error thrown when declaring a top level for-loop iteration variable the same as a function parameter (r217200)


Improved error message for Access-Control-Allow-Origin violations due to a misconfigured server (r217069)


  • Added support for painting MSE video-element to canvas (r217185)
  • Fixed captions and subtitles not showing up in picture-in-picture for MSE content (r216951)
  • Fixed media element reporting hidden when in picture-in-picture mode and tab is backgrounded (r217223)

The full release notes can be found at You can download the latest release of Safari Technology Preview here. If you already have it installed, you can update it from the Mac App Store’s Updates tab.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.