I've used this addon for many years and I honestly love it, but I found an issue that unfortunately I cannot overlook at work- it doesn't save history. If you don't need your history after closing the browser then this is a 5-star addon, and that's why this still gets 3 stars despite the fact that I cannot use it anymore.

The default Firefox session manager saves the history of every tab, and that is incredibly important for me, and leaves me between a rock and a hard place. I have to use a cloud software for work. It logs you out every so often and when you sign in, it will generally bring you back to where you were; however, when you restart your browser it resets the session and after you login it lands you on the main page. If you have you tab history, you can navigate back to the previous page and continue where you left off, otherwise you're stuck with 50 useless tabs and a mess trying to figure out what you were doing. On the other hand the Firefox session manager can save only one session ad is incredibly inconsistent, it's a coin flip whether it will work after a crash and the only way to guarantee a session is saved is by killing Firefox from task manager. If you sign out of your Windows account, restart, or you OS crashes, and you forgot or where unable to kill Firefox from task manager, you're completely screwed.

If it were possible for this addon to save tab history I'd still be using it.

Is there a way to save into the same session instead of creating new one every time I close window? It is more intuitive and more useful.

I would give this extension 1 star, but I can't. Because this is the only one extension, which works for saving and restoring sessions for Firefox. There is no alternative.
I can't give 5 stars however, because extension is very buggy and looks like not even tested by developer properly.

Obvious issues are:
1) If you move tabs between windows - then session tracking gets screwed up Tab Session Manager cannot save this session anymore. Nothing helps. I tried disable/enable back extension. I tried remove extension from Firefox and re-install it back. Nothing helps. Moving tabs between windows is Firefox core functionality. Also its possible to move tabs between private windows. This makes it impossible to organize tabs across multiple windows when using Tab Session Manager.
2) Tab Session Manager export-import extension settings - doesn't work properly. After you import settings you notice that many options are not respected by export and do not restore back. A lot to list them all, but for sure I remember: theme, auto-save intervals, backup and other options.
3) Keyboard shortcuts for saving sessions - do not work at all. No matter which key combination, I tried everything. Only one shortcut works - open extension menu drop down.
4) Bug in intervals. If you set interval to 60 minutes - nothing gets saved every hour. I had to set to 50 minutes because of this.
5) If tracking is screwed up because any unknown reason - then it's impossible to reload extension and re-capture current session and it will always fail to save current session.

But what really works great is regular popup that asks about donations.
I would happily donate, but currently I am not aware if developer cares at all about above mentioned issues, whether those will get fixed.

Very interesting extension, but there are shortcomings, especially in terms of optimizations after 1000+ saved sessions it starts to lag, freeze, etc., developers, do something about this, optimize the list of sessions so that when you open the menu, not all sessions are loaded at once, but in parts, or make a page mode instead of scrolling, otherwise it’s a complete disaster with the list of sessions!!!, and by the way, for some reason, the extension works better and faster on Chrome than in Mozilla, but there too, if you save a lot of sessions, it starts to freeze, but in Chrome there is also session-buddy, also good, I recommend it, it’s a pity there is no Tab Session Master analogue for Mozilla.

It would be a very great extension but unfortunately it cannot work together the Tree Style Tab. Yes I know it says it can but it's not true. It can restore the tabs with Tree Style Tab in 1 time of 10 attempts, in other cases I lose the Tree Style Tab settings, what is very annoying and I don't says polite words during that time when I have restore the trees manually. What is not a funny process with more hundreds tabs.

Great Addon but since I installed the SIMPLE TAB GROUPS (STG) extension, it conflicts with it, and causes errors to my Firefox. Please fix that problem.

[Edit] I found on Github that there is newer release - I am waiting for publish [/Edit]

Since few days it prevents Firefox from start. I can't even figure why. I had removed every old sessions, cleared cache and extension storage and reinstalled couple of times. Checked if there is any conflict with other add-ons, turned them all of and then on again, one by one - and every time I turn on Tab Session Manager browser stops work. Nothing helps.

I wonder why it strictly saves the backups to the download folder without the possibility to define another folder.
I don't want to have forced subfolders with more subfolders in my downloads folder.

It's extremely annoying, that clicking a saved link, keeps the addon popup open until I manually click outside.

Two missing things

This is a good addon, but there are two missing things which are the following:

The first thing:
the history of any tab in a saved session is not stored, so after opening a saved session and loading a tab I can not go backwards to the previous addresses that I visited before saving the session and closing the window of Firefox

this behaviour is not like what was in the great addon
Session Manager by Michael Kraft that was in before Firefox change to web extension addons

I mean the addon Session Manager by Michael Kraft that Sienori was inspired by, as he mentioned in section of About this extension

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The second thing:
Also the saved sessions do not save or keep the hierarchy that was created by addon of Tree Style Tab by Piro (piro_or)


I hope Sienori update Tab Session Manager with these two features

On some devices and browsers is Google login (sync) not working.

Since Firefox removed the Session Manager I tried this extension as a replacement. It was nice to have a way to manage sessions but the memory usage is terrible. When I turned off this extension I went from using over 2GB of memory to 500 MB. This was despite limiting how many sessions to save so that it wouldn't consume too much memory. It's not great using Firefox and having it lag after keeping it open for a few days while using this extension.

Just 3* as only all tabs can be saved - should be able to save just SELECTED tabs. And many comments that import doesn't work, maybe because of diacritics or whatever.

Works well, just wish it supported backing up to free services like Nextcloud and Internxt.

right click session, open in existing window does not work

Has the potential to be(come) great, but for now not useful - for me.

You cannot drag closed tabs to different window.
You cannot drag windows to a different session.
Sessions can't be organized in folders.

Tags for sessions are useful, as you can filter them. This is nice.
Auto-track change option is also a good idea, but it has to be activated for each session individually - it seems.

For now it seems a good extension for people who want session syncing for sessions containing multiple windows.
People who want to sync WINDOWS (1 window = 1 subject) will find this extension less useful.

This is only good for interacting with closed sessions - it's not useful for interacting with your current session. E.g. if you keep a large number of windows & tabs open & need help navigating between them, this won't help: Clicking on a tab or a window will open a NEW INSTANCE of that tab or window (which is absolutely not the default behavior I'd look for).

The feature to sync sessions looks like it could potentially be useful - it improves on the current open-tabs sync functionality by giving access to archived sessions. (Which I suppose is the one area where it's useful, but it's not remotely a common use-case for me.)

I noticed that it does not save the history of the tab. i.e., forward-backward transitions in one tab. This is also important. not only restore windows and tabs, but also the history of tabs, position in front to back. tab chronology. not just a tab with one page, but with a list of transitions. this is super important! do it?

I would give higher but to me only having Google cloud as the only cloud backup solution is not a good option as We All Know what Google will do with your data

Why on earth does this addon suddenly need to know my google email when I sync to GDrive? I find that quite suspicious and unnecessary? It worked fine before without those permissions. I really, really liked this addon. But now, not so much

Great extension.

I'd give it 5 stars if only it has RENAME capability on the Session & Link names, as well as DRAG 'N DROP capability of those sessions and links . Please refer to a Firefox extension named 'Session Sync' for reference.