Apple Releases Safari Technology Preview 173 With Safari 17 Features

Apple today released a new update for Safari Technology Preview, the experimental browser Apple first introduced in March 2016. Apple designed the ‌Safari Technology Preview‌ to test features that may be introduced into future release versions of Safari.

Safari Technology Preview Feature
‌Safari Technology Preview‌ 173 adds functionality that is included in Safari 17, coming with macOS Sonoma. There are Feature Flags that replace the Experimental Features section of the Develop menu, and the Develop menu itself has been revamped. Responsive Design Mode has been updated to focus on the responsiveness of a page's design at any height or width.

Available features on ‌macOS Sonoma‌ include Profiles for separating browsing data like History and Favorites, web apps, and improved private browsing mode. Features for all operating systems include Live Text support for vertical text recognition in images and videos, HEIC support, and JPEG XL, a new image format with an improved compression algorithm for better image quality at smaller file sizes than JPEG.

The browser also includes updates for Web Inspector, CSS, Media Queries, Rendering, Editing, JavaScript, Popover, Images, Media, Web API, and SVG.

The current ‌Safari Technology Preview‌ release is compatible with machines running macOS Monterey 12.3 or later, macOS Ventura, and ‌macOS Sonoma‌, the latest version of macOS that Apple is beta testing right now.

The ‌Safari Technology Preview‌ update is available through the Software Update mechanism in System Preferences or System Settings to anyone who has downloaded the browser. Full release notes for the update are available on the Safari Technology Preview website.

Apple's aim with ‌Safari Technology Preview‌ is to gather feedback from developers and users on its browser development process. ‌Safari Technology Preview‌ can run side-by-side with the existing Safari browser and while designed for developers, it does not require a developer account to download.

Top Rated Comments

alwillis Avatar
13 weeks ago

Support for JPEG XL does seem odd. Seems like that ship has passed. Also Google seems to be starting to promote AVIF which is a better compression algorithm and can do video as well.
Many in the web community were pretty upset that Google dropped support for JPEG XL after including it behind a flag for months. JPEG XL has advantages over AVIF, including progressive decoding and the ability to recompress existing JPEG files in a lossless fashion while saving 20% on file size.

I think it's a shrewd move by Apple, getting out ahead of Google with an image format many in the web community really want. However JPEG XL was being viewed previously, it'll be supported on hundreds of millions devices this fall after Sonoma, iOS 17 and iPadOS ship.

The article The Case for JPEG XL ('') covers all of the details.
Score: 3 Votes (Like | Disagree)
PsykX Avatar
13 weeks ago

boo, no profiles except on Sonoma :(
I've gotta say, this is the only reason I want the new Safari. Want to separate Home from Work. Guess I'll wait more!
Score: 2 Votes (Like | Disagree)
alwillis Avatar
13 weeks ago

I downloaded the tech preview but I can't view JPEG XL files - it's not listed in the Developer > Feature Flags section. How do I enable support for it? I'm on macOS Ventura 13.4.1 - is it a Sonoma-only feature?
JPEG XL is Sonoma-only at this point.
Score: 1 Votes (Like | Disagree)
emosewamai Avatar
13 weeks ago

Safari Technology Preview 173 adds functionality that is included in Safari 17
* I know, I am in minority for asking this feature - Split Tabs. I found it super useful than cascading two windows and switching between them, window losing focus etc. Arc Browser is super helpful with this feature.
* Native ad blocking would be great just like how Brave does. Using external ad blockers is hogging my machine/Safari and I end up restarting Safari.
Score: 1 Votes (Like | Disagree)
CostaMoses Avatar
13 weeks ago

boo, no profiles except on Sonoma :(

I've gotta say, this is the only reason I want the new Safari. Want to separate Home from Work. Guess I'll wait more!
you both may want to try Arc Browser - their profiles and spaces work really well. I used Safari for pretty much everything, but switched over a few months ago and am so happy with it! The only thing I miss is how the codes texted to me would autofill on Safari. That is such a nice Safari feature.
Score: 1 Votes (Like | Disagree)
Mr.Mozi Avatar
13 weeks ago
Can someone confirm whether the responsive presets (^⌘R) are back or not? Apple has removed them entirely in Sonoma's Safari 17, making web development quite hard.

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Score: 1 Votes (Like | Disagree)

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