Brilliant. Had been using Tree Style Tab for the last few years but that took a lot of configuring (and re-configuring) and I recently noticed it was significantly impacting start-up time. Had been waiting (for ages!) for vertical tabs to be supported natively, but was very disappointed with Firefox 136.

Decided to give Sidebery a go and I'm impressed. Minimal customisation required to get it looking/behaving how I want, and it has significantly speeded things up.

Thank you!

Amazing extension with a lot of options and customization! Has everything I've been looking for. Take some time to get to know the extension before leaving a 1 star review.

What is the point of this? Theres folder, but then the tabs are all still in full view in the bar. It sounded like it would function like chrome, where you can open and close the folder, so as to, ya know, organize your tabs??? and not have 15 open ones cluttering up the bar? Useless extension

I used tens of browsers with built-in tab organization and profiles the past 8 years, and none of them even come close to the level of organization possible with this extension.
10/5 stars.

Yes, there are a lot of settings, but once you understand how to use it, Sidebery is a must-have for Firefox. By adding the use of “userChrome”, I have an even better experience.

Great extension! It helps maintaining many tabs available and organized, without clogging your browser with too many open tabs. The killer feature is that you can save the session (even automatically) and restore it at a later time.
To me it's a must-have extension if your work is heavily browser-based

When I realized I could have multiple tab panels, wow! Amazing add-on, I don't know if I can go back to horizontal now. Great work!

È la cosa più simile ad Arc Browser vista finora, veramente ottima.

When I open it, I want it to default on 'bookmarks' not 'sidebery'. I'm not going to spent all night with my head buried in Settings trying to figure how to change the default.

Started OK, went well for a couple of days, then just disappeared! Re-installed, no show. Forget it, not worth the hassle!