• Home
  • Apple
  • macOS
  • News
  • Apple Safari Technology Preview 53 Offers Bug Fixes and Feature Improvements

Apple Safari Technology Preview 53 Offers Bug Fixes and Feature Improvements

Apple Safari Technology Preview 53 Offers Bug Fixes and Feature Improvements

Apple on Wednesday released Safari Technology Preview 53, a new version of their experimental web browser, first released in March 2016. The browser allows developers and other interested parties to test features that may debut in future release versions of Safari.

Apple Safari Technology Preview 53 Offers Bug Fixes and Feature Improvements

Safari Technology Preview Release Notes

Release 53

Service Workers

  • Changed to use one service worker process per security origin
  • Changed to use the same SWServer for all ephemeral sessions
  • Fixed promptly terminating service worker processes when they are no longer needed
  • Included the security origin in the service worker process name


  • Added support for VCP encoder on macOS and iOS
  • Fixed the RTCPeerConnection constructor to throw an exception for bad configuration parameters
  • Fixed setting SenderTrack to null calling removeTrack with RTCRtpSender


  • Fixed CSS mask images to be retrieved using potentially CORS-enabled fetch
  • Fixed loading the stylesheet when changing the <link> element rel attribute from preload to stylesheet


  • Fixed invalidating descendants for :nth-child and :nth-of-type pseudo classes only when needed
  • Fixed positioning for text with letter spacing


  • Added Fullscreen API as an Experimental Feature
  • Prevented SVG root from being skipped while marking percentage height descendants dirty


  • Fixed the table row count when role=”row” is added to in DOM


  • Fixed CSS Grid auto repeat tracks computation with definite min sizes


  • Added a query and fragment exception to the History API’s unique origin restriction

Web Inspector

  • Changed “Force Print Media Styles” to not persist across Web Inspector sessions
  • Changed to not show checkboxes for invalid properties in the Styles sidebar
  • Fixed the ability to add a new class by editing the class attribute in the DOM tree outline
  • Fixed an instance of the main WebGL canvas having no reported size in the Canvas Tab
  • Fixed a recording initiated by the user to properly show immediately on completion
  • Fixed session dividers not being added when Console tab is not visible
  • Fixed flashing when switching between nodes in the Styles sidebar
  • Fixed losing focus when editing a property while a page is being loaded
  • Prevented the Shift-Command-Left Arrow, and Shift-Command-Right Arrow keys from switching tabs when focused on color picker text fields
  • Removed redundant tooltips

Users can either download the update from the Safari Technology Preview website, or if they already have the browser installed, they can download it via the Mac App Store. Full release notes for the update are available on the same website.

While the preview is intended for use by developers and advanced users, in order to provide Apple with feedback on the development of the Safari browser, it can be run side-by-side with the release version of Safari. The app doesn’t require a developer account to download and install. For more information, visit the Safari Technology Preview website.