Apple has released Safari Technology Preview 179. The update includes fixes and updates for CSS, HTML, HTTP, Media, SVG, Web API, and Web Inspector.
Safari Technology Preview offers a sneak peek at upcoming web technologies in macOS and iOS. You can experiment with these technologies in your websites and extensions.
Safari Technology Preview is a standalone app that works side-by-side with the current version of Safari, so you can continue to use and reference the current release.