Release Notes for Safari Technology Preview 41

Safari Technology Preview Release 41 is now available for download for macOS Sierra and macOS High Sierra. If you already have Safari Technology Preview installed, you can update from the Mac App Store’s Updates tab. This release covers WebKit revisions 221968-222556.

File and Directory Entries API

  • Enabled File and Directory Entries API (r222412)


  • Added support for min() and max() in calc() (r222190)
  • Added env() as an alias of constant() to match the evolving specification (r222402)
  • Made more of the CSS animation system internals element based (r221980)
  • Prevented fit-content() tracks from stretching (r222440)
  • Removed CSS Regions support (r222435, r222259, r222423, r222356)

Bug Fixes

  • Fixed an issue introduced in Safari Technology Preview 40 where websites would log users out immediately after logging in


  • Fixed RTCDataChannel connectivity issues (r222045)

Drag and Drop

  • Enabled DataTransfer.prototype.items by default (r222376)
  • Expose text/html and text/uri-list in DataTransfer.prototype.items (r222363)
  • Fixed DataTransfer to stop exposing local file paths when dropping files (r222257)


  • Changed history.pushState() and history.replaceState() to align more closely to the HTML standard (r221978)
  • Changed to use a high resolution timestamp for event time (r222392)


  • Added a small optimization for async generators (r222425)


  • Added support for Elliptic Curve P-521 (r222316)


  • Added bindings for optional arguments to some WebGL2 methods (r222258)
  • Enabled passing sequences to various WebGL2 methods (r222026)
  • Fixed accelerated texImage2D for video to respect flipY in WebGL (r222197)
  • Fixed VideoTextureCopierCV to correctly restore vertex attribute state (r222198)
  • Updated some WebGL2 return types to match the specification (r222096)


  • Aligned Media Source Extension IDL with spec (r222443)


  • Changed to avoid style recomputation when forwarding a focus event to a text field’s input type (r222114)
  • Changed to avoid style resolution when clearing focused element (r222164, r222167)
  • Fixed computing animated style to not require renderers (r222129)
  • Fixed partial frame rendering that can occur even after loading all of the encoded data (r222427)
  • Fixed the width of a child’s margin box to always be equal to that of its containing block in regular block layout (r222321)
  • Fixed the spelling, grammar, and correction dots that were being painted upside down (r222065)


  • Fixed ARIA grids that claim to be multiselectable even with aria-multiselectable is set to false (r222527)


  • Added Cache API support of records persistency (r222073)
  • Changed IDBRequest and IDBTransaction error properties to be DOMExceptions (r222250)

Web Driver

  • Fixed an issue that prevented clicking on overflow: hidden elements without children (r222536)
  • Fixed an issue that prevented clicking on <option> elements
  • Fixed an issue that prevented the top-level frame from being re-focused automatically when the main frame navigates

Web Inspector

  • Added auto-completion suggestions for CSS attr based on the selected element’s attributes (r222483)
  • Added auto-completion suggestions for CSS functions such as constant(), env(), linear-gradient(), etc. (r222359)
  • Changed pressing the Escape key in the global search field to clear the field (r221990)
  • Changed the keyboard shortcut for “Reload page from origin” to match Safari (r222338)
  • Fixed updating the Event Listeners section when listeners are added or removed (r222002)
  • Fixed “Sort by size” issues with Cookies and ApplicationCache DataGrids (r222001)
  • Updated user agent strings and iPhone 8 / iPhone 8 Plus models in Responsive Design Mode