I'm not a Vivaldi user, but just based off their feature page, you might be interested to check out some of the features/extensions: 1. Firefox's native tab gr

I'm not a Vivaldi user, but just based off their feature page, you might be interested to check out some of the features/extensions: 1. Firefox's native tab groups [^1] 2. Sidebery's panels (if you don't mind vertical tabs) [^2] 3. Simple Tab Groups [^3] [1]: https://www.firefox.com/en-US/features/tab-groups/ https://www.firefox.com/en-US/features/tab-groups/ [2]: https://addons.mozilla.org/en-US/firefox/addon/sidebery/ https://addons.mozilla.org/en-US/firefox/addon/sidebery/ [3]: https://addons.mozilla.org/en-US/firefox/addon/simple-tab-groups/ https://addons.mozilla.org/en-US/firefox/addon/simple-tab-gr...