Release Notes for Safari Technology Preview 76

Safari Technology Preview Release 76 is now available for download for macOS Mojave and macOS High Sierra. If you already have Safari Technology Preview installed, you can update in the Software Update pane of System Preferences on macOS Mojave and from the Mac App Store’s Updates tab on macOS High Sierra. After updating to macOS Mojave, you may have to reinstall Safari Technology Preview.

This release covers WebKit revisions 240780-241432.

Dark Mode

  • Fixed overflow element scrollbar for dark mode content


  • Fixed RTCRtpSender.getCapabilities(“video”) before initial offer breaking VP8


  • Simplified and streamlined code that creates an appropriate document based on MIME type
  • Aligned with Fetch on data: URLs


  • Fixed scroll-snap-align to be honored on a child with non-visible overflow


  • Added basic scrollability for async overflow scrolling
  • Fixed first paint getting blocked by async or deferred scripts
  • Fixed jumpy async overflow scrolling if the main thread is busy
  • Fixed rendering for async overflow scroll with border-radius

Payment Request

  • Updated to allow requiring a phonetic name for shipping contacts


  • Updated inline WebVTT styles to start with ::cue
  • Updated to always stop ducking audio after audio capture ends

Web Inspector

  • Added the ability to Import and Export Heap Snapshots
  • Added context menu items to copy a resource’s HTTP request or response data
  • Added keyboard shortcut to the Export button tooltip in the Audit tab
  • Added icons for media event types
  • Fixed selection getting broken after deleting the selected node
  • Fixed the Memory timeline starting from zero when both CPU and Memory timeline are enabled
  • Fixed missing resource data for the document on reload in the Resources tab
  • Fixed timeline Detail views to reset properly when a new time range selection contains nothing in the Timelines tab
  • Fixed timeline graphs that have drawing issues with multiple discontinuities in the Timelines tab
  • Fixed timeline time range selection to show duration alongside start and end in the Timelines tab
  • Fixed clicking on an empty space in the overview to deselect any selected record bar in the Timelines tab
  • Reduced the time spent updating related resources in the Details sidebar of the Resources tab when loading a page with lots of resources
  • Updated the Styles sidebar to automatically close unbalanced quotes and parenthesis when editing values
  • Updated the Styles sidebar with an easier way to select a single line

Browser Changes

  • Added a “Reset All to Defaults” option in the Experimental Features menu of the Develop menu