Safari Technology Preview 41 for Mac Release Offers Bug Fixes and Feature Enhancements

Posted in Apple News, macOS on 05/10/2017 by Chris Hauk


Safari Technology Preview 41 for Mac Release Offers Bug Fixes and Feature EnhancementsApple on Wednesday released Safari Technology Preview 41, 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.

Release 41 includes bug fixes and improvements. The update also enables the File and Directory Entries API. (Via MacRumors)

With the recent release of macOS High Sierra, Apple is now providing two versions of Safari Technology Preview, one for macOS Sierra systems and one for macOS High Sierra systems.

Release 41

File and Directory Entries API

  • Enabled File and Directory Entries API


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

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

Drag and Drop

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


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


  • Added a small optimization for async generators


  • Added support for Elliptic Curve P-521


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


  • Aligned Media Source Extension IDL with spec


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


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


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

Web Driver

  • Fixed an issue that prevented clicking on overflow: hidden elements without children
  • 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
  • Added auto-completion suggestions for CSS functions such as constant()env()linear-gradient(), etc.
  • Changed pressing the Escape key in the global search field to clear the field
  • Changed the keyboard shortcut for “Reload page from origin” to match Safari
  • Fixed updating the Event Listeners section when listeners are added or removed
  • Fixed “Sort by size” issues with Cookies and ApplicationCache DataGrids
  • Updated user agent strings and iPhone 8 / iPhone 8 Plus models in Responsive Design Mode

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 Tech Preview website.


Chris Hauk

MacTrast Senior Editor, and self-described "magnificent bastard," Chris Hauk owns Phoenix Rising Services and writes for everyone's favorite "bad movie" website, Big Bad Drive-In.

His first Apple product was an iPod Classic 9 years ago, and he has since added a MacBook Pro, a number of iPads, iPhones, and multiple Apple TVs to his collection.

He lives somewhere in the deep Southern part of America. Yes, he has to pump in both sunshine and the Internet.