It does the job as it should! No complaint, till today that it double saves my open tabs. For example, if i have 2 windows and 50 tabs on each, it saves and opens 4x windows and 200 tabs. I use this extension for a long time now (years), without complaint. I don't know if it's firefox fault or the extension. Please take a look at this Sienori, thank you!

I tried Tab Manager Plus but found it USELESS. It doesnt save sessions like it says it does but this one I installed and BOOM, So easy to click on it and choose save session, thank you!

Destroying my tab groups every launch. All Tab Groups need to be recreated, all tabs need to be readded to their groups. Disabled until this is supported.

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.)

Works really well. I would like functionality to name windows and have that title persisting after saving and restoring a window or session. I'm using extension Window Titler that prefixes the name of the window with [MyTitle], followed by the name of whatever tab is currently open (so window title changes dynamically). That functionality is perfect, but that title is obviously lost when window is saved.

I have a problem: TSM doesn't save tab groups after I reopen Firefox. It opens all the previously opened tabs, but not in groups.

This extension is almost but not exactly quite what I am looking for. I really really dig the idea but the way that sessions work essentially just makes this a more complicated history tab. I would like the option to update and overwrite an auto save instead of creating a whole new save. With autosave a new save is created that overwhelms manually created sessions. I would expect the behavior that each window is an independent save and duplicates are not created. Additionally with events such as window and browser closing, the save feature creates multiple identical and redundant sessions.

Not restoring previous.jsonlz4

Tab Session Manager has been working largely without problems for years.
However, since April 6, automatic saving is no longer carried out, neither automatic saving, nor regularly saving the session, nor saving the session when the browser or window is closed.
There are approx. 1800 open tabs

On two different ff versions 91.9.1 and 115.20 it randomly deleted ALL sessions, on one ff i lost a sessionwith 2000 tabs and on the other 1800 tabs, backup is disabled by default, no other backups are kept and recovery is possible only if you have all your history from the past 6 months. evrything else is pretty good.

used to work but recently after the notorious Firefox update it's now broken and author does not respond.

After several months of using I can say: Absolutely Vital. When you don't want to close a window (just in case you possibly would miss the tabs), save the window instead. No more gazillions of windows, and no tab is lost.

works