Try Out The New Safari 15 Features With Safari Technology Preview

The newest version of Safari Technology Preview, version 126, is available for people on macOS Big Sur and the macOS Monterrey betas. It contains previews of features we’ll see with Safari 15 when Monterrey is released this fall.
Safari Technology Preview 126
From the WebKit announcement:

Streamlined tab bar. Use Tab Groups to save and organize your tabs. Experience the new design. Test your site. Experiment with theme-color.
Live Text. Select and interact with text in images on the web in macOS Monterey betas on M1 Macs.
Improved Safari Web Extensions. Try out the support for declarativeNetRequest, which expanded to 150K content blocking rules and non-persistent background pages for improved performance.
Quick Notes. Add links and Safari highlights to remember important information or ideas on the web in macOS Monterey betas.
WebGL 2. Try out the improved 3D graphics performance of WebGL running on top of Metal via ANGLE.
Web technologies. Experience and test the HTML, CSS, JavaScript, and other web technologies that are available in Safari 15 Beta and included in previous Safari Technology Preview releases.

You can download Safari Technology Preview here.
Tags: Mac, Safari, WebKit