Apple releases first update to Safari Technology Preview browser

Apple has released the first update to Safari Technology Preview browser.

Safari Technology Preview Release Notes

Release 2

Browser Differences
• Changed the CFBundleSignature to allow Apple Events, like those sent from AppleScript, to correctly distinguish between Safari and Safari Technology Preview

• Added ES6 support for Symbol.isConcatSpreadable
• Disallowed var assignments in for-in loops according to ES6 specs
• Improved stability for ES6 classes when invoking a method of the parent class before calling super() in a constructor
• Allowed undefined or null for and Symbol.match
• Enabled Array.prototype native functions’ species constructors to work with proxies
• Implemented the proposal for String.prototype.padStart() and String.prototype.padEnd()
• Implemented ES6 spec for String.prototype.match and RegExp.prototype[@@match]
• Included a workaround for web compatibility on ES6 TypeErrors when accessing RegExp.prototype flag properties
• Corrected quantified unicode regular expressions
• Ensured greedy unicode regular expressions properly backtrack past non-BMP characters

• Implemented the allow-end value of the hanging-punctuation CSS property
• Improved web compatibility by resetting CSS spacing rules on elements
• Added the new color-gamut CSS media query
• Updated screen queries to check the capabilities of the current screen instead of the deepest available screen

Web APIs
• Restricted WebSockets header parsing according to RFC6455 and RFC7230
• Improved performance of certain draw calls in WebGL with a non-power-of-two texture optimization
• Disabled the Fetch API until the implementation is ready to be enabled by default
• Enhanced Shadow DOM support to compute styles for the style attribute of elements
• Softened pushState and replaceState frequency restrictions

Web Inspector
• Timelines tab performance and bug fixes
• Disabled debugger statements while profiling a page to ensure maximum performance accuracy
• Added the ability to configure timeline instruments to use for recordings
• Added a paint count indicator in the top left corner of non-opaque layers
• Added font-variant-numeric to CSS autocompletions
• Added the console.takeHeapSnapshot method for capturing heap snapshots
• Changed details sidebar shortcuts to Command-Option-0 and Command-Shift-0
• Double-quotes and backslashes in strings are now displayed correctly in the console
• Improved the consistency of CSP directive violation messages reported in the console

• Corrected new lines in content editable elements to notify accessibility
• Updated the handling of SVG elements with a presentational role to be the same as other host language elements
• Limited the numbered list announcement for a list item number to the first line of text in the list item
• Changed the accessibility role descriptions for JavaScript alerts to “web dialog” and “web alert dialog” to make them more understandable to screen reader users

• Updated backdrop filter to repaint when changed in JavaScript
• Corrected drawing SVG stroke patterns for objects with empty bounding box elements

• Improved stability when an audio source is changed while being processed
• Fixed audio track listings

• Improved the reliability of speculative disk cache validation requests with the HTTP Referer header

Bug Fixes
• Fixed autoscrolling in a drag selection when a window is against the screen edge, including while in full screen mode

More info and download links here.

[Thanks to MacDailyNews Readers “Fred Mertz” and “Albert P.” for the heads up.]


  1. Looks pretty good, thanks for the tip.

    However, one of my first sites was this page and … OMG, I could not see the news let alone a place to enter this note but for the ADVERTISEMENTS, pop up videos, etc.


      1. A good example of offensive is the Home Depot ad that is currently occupying the bottom 1/6 of my screen. If you even let the cursor hover over the ad it starts a countdown to a full screen, auto play video.

        Little do they realize that there is no universe in which I will respond positively to that ad. Home Depot is dead to me at this point. They might as well burn down all of their stores.

      1. Even on the app there are 5 ads including auto play video ads. I can put up with the static ads but the video ads eat up my data allowance. And don’t get me started on the ads that redirect you to the App Store (even in the MDN App)😡

  2. Joe wrote: “If this site is so disturbing, frustrating, and annoying to you, precious little snowflake, please, do not return.” Joe with all due respect you are missing it: I brought it up because I would like to see improvement, and when I did suddenly many others seem to agree with me. It would be nice if MDN got the message as well. If you can’t see that Joe, then I respectfully suggest it’s time for your nap.

    pr: thanks for your comments.

    To all who mentioned AdBlock, I use that on the regular version of Safari, but wanted to try out the “Preview” just as it is… and *that’s* when I ran into the sea of adverts. Let’s all hope that MDN does something positive about fixing the problem. In their defense, they have not censored me, and that’s appreciated.

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