I'm under the impression that this is the way Firefox's vertical tabs should work.
Certainly, not for novice users, but maybe simply an optional "Advanced Mode" or something similar, that we could just enable from Settings and then have this kind of extremely versatile and powerful tabs, groups, etc., tools at hand.
Still trying it and already liking it a lot.

One of the main reasons why I just recently switched (at least for now) from Edge to Firefox / Floorp. I like it better than the vertical tabs feature in Edge. More compact and more features. Thanks

As close as I can get to mimicking Arc on Firefox

This extension is really useful

If you are using Firefox on desktop or any other Gecko-based Firefox browser like Zen browser, or Floorp browser or Librewolf browser, and not using Sidebery extension, then you are missing a lot.

Purely a horsepower experience for someone who uses it for office work and has tabs over 300 open and rarely closes them for months.

Used it for years and but never took out a time to review or even rate it so here it is.

Hey, dev, you rock.

Keep updating and improve the icon of the addon here and on the extension tab, as it unrecognizable on the bar once any other theme is used.

A little bit of additions of more fonts of the tabs in the side bar and a better display ratio under appearance for font size would be great.

Since Firefox doesn't have any tab suspension or tab hibernation option in-built like Chrome 130 has, it would be great something like that sort is considered without re-activating the tab on browser restart or tab visit (see tab suspender addon on chrome and it settings). Very much needed as Firefox consumes too much of data and memory of such usages as compared to other browsers.

Also, the tab count number is unreadable since it is not differentiated from the background color. Try to enhance it and make it readable.

And, cloud backup with Firefox account and exactly restoring on another device or reinstalling if anything happens to the existing browser on which this addon installed would be a charm.

Thanks, dev and keep it up.

You make using Firefox and Firefox-based browser usable in a better way even what Google Chrome cannot in 2024-25.

Sideberry makes tabs slick as hell. I appreciate the ability to use a custom font (determined from Firefox defaults I think). Running Sideberry along with the mod to remove default top tabs, plus the add-on 'hide-scrollbars' adds so much space to the screen and feels super clean. Make sure to go through the settings to suit your preferences, using the option 'Switch tabs with scroll wheel' is so convenient!

Moved back to Firefox from Edge so I could have tabs on the right. Crazy, I know. But Sideberry makes it possible and so much more. 🌟

mbnuqw, thank you. I appreciate you making this extension. It has been an amazingly powerful tool for my work.