Release Notes for Safari Technology Preview 102

Safari Technology Preview Release 102 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 256576-257162.

Web Inspector

  • Fixed VoiceOver to read the selected panel tab (r256652)
  • Updated resource, type, and timeline icons for both light and dark modes (r256774, r257043)


  • Changed the disk cache policy to allow resources larger than 10MB to be cached (r257041)
  • Defered execution of async scripts until the document is loaded (r256808)
  • Fixed value sanitization for input[type=text] to not truncate the value at a control character (r257132)
  • Fixed new FontFace() to not throw when failing to parse arguments (r256659)
  • Implemented EventTarget constructor (r256716)
  • Set User-Agent in preconnect requests (r256912)


  • Improved the speed of index cursor iteration when there are a lot of index records from different object stores (r256738)
  • Changed to prefetch cursor records on client side (r256621)

Apple Pay

  • Added support for Apple Pay buttons with custom corner radii (r256648)

Web Animations

  • Ensured CSS Transition and CSS Animation events are queued, sorted and dispatched by their timeline (r256619)
  • Ensured animations that lose their effect don’t schedule an animation update (r256623)
  • Fixed repeated animations on pseudo elements failing to run after a while (r257138)
  • Fixed style changes due to Web Animations to not trigger CSS Transitions (r256627)


  • Improved performance of track sizing algorithm for spanning items (r256826)


  • Changed to not fire timers when there is a pending rendering update (r256853)
  • Fixed a white flash that can occur if JavaScript forces an early layout (r256577)

Web Driver

  • Fixed Automation.setWindowFrameOfBrowsingContext to accept negative origin values (r257042)