Release Notes for Safari Technology Preview 88

Safari Technology Preview Release 88 is now available for download for macOS Mojave and the macOS Catalina beta. 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 247047-247433.


  • Enabled Intl.PluralRules and Intl.NumberFormatToParts by default (r247247)


  • Registered a MediaStreamTrack as media producer only if it is a capture track (r247208, r247382)


  • Fixed XHR CORS requests getting logged twice on the server (r247276)

Pointer Events

  • Updated to respect pointer capture when dispatching mouse boundary events and updating :hover (r247148)


  • Changed to avoid extra backing store on elements with overflow: scroll and visibility: hidden (r247420)
  • Changed to trigger a compositing update when a video element is changing (r247187)


  • Added accessibility announcement notifications to show, dismiss and selection change for the datalist suggestions view (r247418)
  • Exposed HTML datalist accessibility (r247295)
  • Enhanced support of aria-haspopup per ARIA 1.1 specification. (r247071)
  • Implemented support for ARIA roles: insertion, deletion, subscript, superscript, and time (r247349)
  • Fixed ignored role="presentation" on HTML <table> elements for VoiceOver (r247330)


  • Hooked up WebGL’s back buffer in ANGLE backend on macOS (r247315)


  • Added most of the remainder of the standard library (r247174)
  • Implemented GPUError and error scopes (r247366)
  • Made the destructor of VariableDeclaration non-virtual (r247124)
  • Optimized the lexer (r247171)
  • Removed the phase resolveCallsInFunctions (r247170)

Web Inspector

  • Added support for pasting copied DOM nodes in the Elements tab (r247054)
  • Fixed dismissing a blank property to no longer cause the rule to appear in the Changes panel (r247406)
  • Fixed an issue where unbalanced quotes or parenthesis weren’t displayed as properly closed after editing values (r247196)
  • Updated descendant DOM breakpoints be enabled, disabled, or deleted from a collapsed parent (r247053)

Bug Fixes

  • Fixed paste from Notes into Excel 365 spreadsheet (r247222)
  • Fixed video playback on on macOS Catalina (r247213)