Release Notes for Safari Technology Preview 106

Safari Technology Preview Release 106 is now available for download for macOS Catalina and macOS Mojave. If you already have Safari Technology Preview installed, you can update in the Software Update pane of System Preferences on macOS.

This release covers WebKit revisions 260266-261057.

Web Inspector

  • Sources
    • Ensured “Step Over” only steps through comma expressions if they not nested (r260520)
  • Storage
    • Fixed third-party cookie display (r260807)
    • Added support for selecting multiple local storage entries (r260613)
  • Miscellaneous
    • Updated find dialog to populate the search string from the system find pasteboard (r260847, r260887, r260895)
    • Fixed the filter bar in the navigation sidebar to respect the global search settings (r260386)

Async Scrolling

  • Enabled async frame and overflow scrolling by default on macOS (r260276)
  • Fixed an overflow that’s hidden on one axis to be scrollable on that axis (r260450)

Web Animations

  • Fixed applying keyframe easings to transforms (r260360)
  • Changed to guarantee assigning an element to keeps the element alive, even without other references to it (r260705)
  • Implemented jump-* functions for steps() timing functions (r261046)


  • Added support for :where() pseudo class (r260319)
  • Fixed :is() and :where() to not allow pseudo-elements when parsing (r260338)
  • Fixed border-radius failing to clip composited iframe contents (r260950)


  • Enabled BigInt (r260345)
  • Changed BigInt constructor to accept larger integers than safe-integers (r260863)
  • Added support for Intl.RelativeTimeFormat (r260349)
  • Redesigned for-of iteration for arrays (r260323)


  • Updated getDisplayMedia to respect aspect ratio with max constraints (r260561, r260638)


  • Fixed the visibilitychange event to bubble per spec (r260483)


  • Changed to ensure a remote track event gets unmuted after the track event is fired (r260813)
  • Fixed audio session category to be set incorrectly after changing video source with MSE (r261004)
  • Fixed video elements to return to an incorrect position when exiting fullscreen (r260150)


  • Fixed flickering header when scrolling articles with fixed position elements (r260828)
  • Fixed content disappearing in a CSS-based parallax implementation (r260371)
  • Fixed a blank header on a site by changing to not use stale containing block width value while computing preferred width (r260905)
  • Fixed oversized caret and selection rects in text fields (r260367)

Bug Fix

  • Enabled using credentials for same-origin CSS mask images (r260598)