Release Notes for Safari Technology Preview 51

Safari Technology Preview Release 51 is now available for download for macOS Sierra and macOS High 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 228454-228856.

This release of Safari Technology Preview may reset your homepage and search engine preferences to Safari’s defaults.


  • Added accessibleclick event (r228827)


  • Disallowed cross-origin subresources from asking for credentials (r228486)
  • Prevented blocking authentication challenges to navigated resources (r228703)


  • Fixed provisional loads that might get committed before receiving the decidePolicyForNavigationResponse response (r228852)

Service Workers

  • Fixed the ability to download resources loaded from Service Workers (r228551)


  • Changed to handle all SVG writing modes (r228822)


  • Improved the speed of descendent selector invalidation by using a selector filter (r228729)

Web Inspector

  • Added support to show or hide the navigation sidebar panel based on the current view (r228722)
  • Fixed hiding the completion popover when switching panels in the Styles sidebar (r228487)


  • Added support for scrolling a non-editable web-selection and start autoscroll when near screen edges (r228549)