Apple has released Safari 15 for macOS.
Safari 15 delivers faster performance, improved security, and the following new features:
• Tab Groups help you save and organize your tabs and easily access them across devices
• Redesigned tabs have a rounder and more defined appearance and take on the color of the webpage
• Compact tab bar option shows more of your web page on screen
• HTTPS upgrade automatically switches sites from HTTP to more secure HTTPS when available
For detailed information on the security content of this update, please visit: https://support.apple.com/kb/HT201222
You can download Safari 15 from Software Update in System Preferences.