Release Notes for Safari Technology Preview 74

Safari Technology Preview Release 74 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 239566-239991.

Fetch API

  • Implemented abortable fetch (r239644)

Web Animations

  • Changed to compute animation effect timing properties in batch (r239723)

Web Authentication

  • Changed the nonce in the CTAP kInit command to weak random values (r239852)
  • Imported U2F command and response converters from Chromium (r239665)
  • Added support for U2F HID Authenticators on macOS (r239752)


  • Enabled MDNS ICE candidate support by default (r239936)


  • Changed <video> elements to not enter “paused” state when playing to the end over AirPlay (r239857)
  • Defined page media state flags for display capture (r239840)
  • Changed to deactivate audio session whenever possible (r239694)



  • Added an override of the session configuration for cookieAcceptPolicy (r239832)
  • Enabled visual viewport API by default (r239897)
  • Changed to no longer trigger a main frame load when doing a history navigation if the source and destination history items are clones
  • Fixed Bulgarian TLDs to not punycode-encode URLs with Bulgarian Cyrillic characters (r239967)
  • Fixed an issue where view is unresponsive for 5 seconds after swiping back on sites like (r239720)
  • Fixed the parsed protocol of JavaScript URLs with embedded newlines and carriage returns to match the parsed protocol in Chrome and Firefox (r239642)
  • Fixed unwanted page navigation after showing and dismissing contextual menu with control-click (r239686)

Service Workers

  • Fixed Service Worker fetch handler that resulted in a bad referrer (r239749)
  • Updated Service Worker fetch to obey its referrer policy (r239659)


  • Optimized Object.prototype.toString (r239612)


  • Updated the accessibility string for the <hr> HTML tag to use “separator” instead of “rule” (r239613)

Web Inspector

  • Added a Setting toggle for Source Maps (r239635)
  • Added the ability to allow audits to be enabled or disabled in the Audits tab (r239858)
  • Added the ability for audits to determine whether a give node has event listeners when running an audit (r239987)
  • Added the ability for audits to query for all nodes with a given computed Accessibility role when running an audit (r239986)
  • Changed to automatically disable breakpoints when running an audit in the Audit tab (r239646)
  • Changed the Network tab to show secure connection details per-request (r239698)
  • Changed to use the save sheet instead of a dialog when clicking the “Export” button in the Network tab (r239647)
  • Extended XHR breakpoints to work with Fetch (r239703)
  • Fixed the color picker to accurately show color when the saturation value is not 100% (r239597)
  • Fixed support for “white” as a recognized color keyword (r239690)
  • Fixed text field and completion popover fonts to match in the Events breakpoint popover (r239953)
  • Fixed showing completions for events that start with “DOM” when typing uppercase “DOM” in Event breakpoints (r239955)
  • Fixed vertical alignment of group titles in the Settings tab (r239932)
  • Fixed read-only properties from being able to be deleted in the Styles sidebar (r239585)
  • Fixed pressing down key on an empty value field discarding the completion popover in the Styles sidebar (r239935)
  • Fixed selection becoming lost in the Styles sidebar when Web Inspector is blurred (r239588)
  • Fixed undo to prevent it reverting all changes at once in the Styles sidebar (r239762)
  • Implemented queryObjects Command Line API (r239583)
  • Included globalThis in default JavaScript completions (r239630)
  • Prevented starting a selection when clicking on a property that is being discarded in the Styles sidebar (r239766)


  • Changed element click and other commands to appropriately handle user prompts (r239610)
  • Updated the Create Window implementation to support the newest specification (r239988)


  • Fixed IndexedDB storage of Crypto keys in private browsing mode (r239746)
  • Fixed deleting IndexedDB databases to ensure open databases are not missed (r239960)
  • Made “Disable Web SQL” on by default (r239885)


  • Fixed CSP violation reports to bypass CSP checks (r239634)