The current Safari Technology Preview builds on the Safari 16 update, including support for macOS Ventura features such as live text, passwords, web extension improvements, and more. Unlike previous versions of Safari Technical Preview, the new version is compatible with machines running macOS 13 Ventura, but no longer works with macOS Big Sur.
Safari Technical Preview updates are available through System Preferences - Software Update to users who have downloaded the browser. Apple launched the Safari Technology Preview to gather feedback from developers and users on the browser development process. The Safari Technology Preview runs side-by-side with the existing Safari browser and is designed for developers, but can be used without a developer account.