It has many features... but lacks the most important one: it saves open sessions as new ones, not updates them!!
Still cannot find a replacement for the old good Sync Tab Groups........ :'( This one is NOT.

Worked well for years. Sometime last year it broke, all my sessions disappeared from the list and it will only save the last session. I think I did something that fixed it, or it fixed itself and I was able to get all my stuff back (thought I am unable to recreate what I did).

But now it has happened again and this time it does not seem recoverable. The export option in the extension settings does not even work.

Not reliable, wish I could rate it higher but I am now screwed because of this. So much time will need to be wasted to get all my research and prep work back.

Find an alternative that doesn't break/wipe itself as much and has more reliable backup methods.

I had been using it for a long time without issues, it saved me 2-3 times; but yesterday my computer crashed. My waterfox session file must have been corrupted and it restored it from the recovery one (previous.json) that is somehow 2 months old (thank you mozilla for not updating it more frequently). I immediately went to tab session manager to restore; but surprise surprise, all the backups are gone. At some point it seems the automatic backup feature stopped working and somehow even the older sessions disappeared. Idk if it was a browser update, error or that they were older than X and automatically deleted.
TLDR, even having this extension enabled to prevent the loss of my session, I still lost my session. I will either look for an alternative extension and/or start backuping the session file manually.

The only problem that I have with TSM is that it does not play nicely with Simple Tab Groups at the moment. I use STG all the time, so unfortunately until this bug is sorted, TSM is a non-starter for me. Which is unfortunate because it is highly recommended and I would like to use it. (P.S.: I run a Mac using Monterey so quite old, nevertheless, this post is accurate as at 2025-05-08.)

Was very good. Now completely unusable only on Firefox as it ungroups Tab Groups despite having support for it

Unfortunately it looks like this is not maintained regularly. It caused all favicons to disappear. It took me a good 20 mins to find it out and there's no doubt it was this extension causing that. It took me another 20 minutes to report the bug with all details on github, but after 2 weeks, still no response.

The extension would be useful, unfortunately it has already happened to me a few times, that when restarting Firefox the tabs opened when closed are not restored. Unfortunately I lose many tabs that I can not recover and I do not like this, so I have to uninstall the extension.

Ele funcionava bem há alguns anos, mas não salva mais as sessões automaticamente, seja por tempo, seja ao sair do Firefox, somente salva quando salvamos manualmente - e, mesmo assim, pode manter apenas a última.

Originaly I would had given it five stars.
Sadly I've recently lost multiple sessions. SInce then, I lost all trust I had on its reliability so two stars it is.

Newest update broke keyboard shortcuts.....

Tab Session Manager was my session manager of choice until I realized that it was at fault for a very annoying problem I was having.

I still use Windows 10 on my main computer and I run many multiple desktops. Sometimes up to twelve.

With TSM active, every time I restarted Firefox, all of its (many, many) windows—which had been distributed across multiple desktops—would open on a single desktop, leaving me with several minutes of work to reorganize them into something coherent.

As well, browser windows that I'd long since closed were also opening, adding to the clutter.

Eventually this became too annoying and I started probing into the cause. Disabling TSM immediately made the issue go away so I left it disabled and started using Tab Stash, which I don't like as much but when I restart FF all the windows stay where I had them.

I'd go back to TSM in a second if I knew the multiple desktop issue had been sorted.

A tad bit confusing to use at first. Once I got the hang of it it wasn't bad. What I don't like is I am unable to just save a single tab. It forces me to save all tabs in a session. Not what I want. When I find a specific page I want to save only I can't.

Will randomly reset its shortcut keys even after you've removed them.

It was working for me, but recently I've started getting massive memory leaks (like Firefox takes 8+GB of RAM and continues to take more causing swap and everything works slowly). After turning this extension off, all is back to normal.

Mixed performance... for a while it worked then stopped, then worked, then worked but looked like it stopped because saved sessions were not showing.

Session restore sometimes does NOT remember the order of the tabs, sometimes opening them in backwards order, sometimes just switching a few around.

Also, does not remember containers... so containers in a session are lost. So you have to remember which tabs are in which and reopen them.

Unfortuntely, this seems to be the best there is at this time.

Good when it works but regularely stops working, its supposed to save every 15 minutes and when the browser is closed.

The newest save is more then 3 weeks old making this addon pretty much useless.

:\ having trouble closing tabs from within TSM because the scroll bar on the right covers the X buttons

could you please move the X's to the left of the tab names or make the scroll bar smaller please? I am using most recent Firefox..

Good for autosaving sessions but tracking does not work ok. When using startup session it stop being tracked and not updated, is just one more saved session

Suddenly one session saved for later and renamed changed its name

Uninstalling extension, is almost unusable

I used to love this add-on, have been using forever, but I don't think it's supported anymore. Synch with Google Drive no longer works, and issues aren't being addressed. It was a good run.

Used to work perfectly for me, but for a while now when i open a session in a new window, all other firefox windows are closed automatically

Well this worked all of once for me... Click import session, it says it was imported, then loading session nothing is there

Works somewhat, but
* loses open tab favicons between restarts
* always reloads all tabs one at a time after Firefox has already restored them (with favicons!)
* recently wouldn't even properly reload tabs, but give me errors. I had to manually reload them.
Due to all these issues, I'm looking elsewhere.