It is a great add-on. But if you also use containers and you will restore a session all tabs are moved to the default container. I had 15 containers and aprox. 350 tabs. It takes hours to move each tab back to the container (I did not found a add-on for "mass-moving" tabs to containers). If you do not use containers: It is the right add-on for tab session. For containers + sessions search for 'session boss'.

The best currently for Quantum.

Thank You So Much Dear "Sienori" , For This Brilliant addon , Excellent addon

excellent, the best session manager at the moment. if i may, i'd like to point out a little problem regarding favicons and (i think) "auto tab discard" extension: when TSM saves a session with some "discarded tabs" by that extension, the modified favicon disappear when reopening the session.

Works great but the only issue I have is when i restore a session sometimes it will also restore my bookmarks and open them up in tabs so a session that was like 5 tabs when I restored it suddenly has over 100 tabs.

This is a must-have, life-saving add-on! Ever since TabMix Plus stopped working, I was looking for an add-on that would ensure that my tabs are restored when Firefox has a bad crash and can't restore itself.
But this add-on does so much more. It allows you to store your session manually or automatically. So whenever you notice that you are missing a tab (web page) from a few weeks ago, chances are good that you can find a backup.

Phenomenal!! Essential for my productivity. Cannot recommend highly enough

Does Tab Session Manager supports Simple Tab Groups? What should I do if FF suddenly crashes? Will Tab Session Manager restore all my tabs AND GROUPS?

>>>PLEASE ADD ABILITY TO "LOCK" SAVED SESSIONS! The delete button is not forgiving, (no undo/undelete...and the "restore" option only lasts a few seconds!)....so please add option to LOCK, located next to the OPEN and DELETE options. thanks...great app. *********please update as soon as you can! THANKS AGAIN! :)

OPEN - DELETE - LOCK!

this is a great little add-on. so many times, while drunk i have closed windows to come in the next morning to wonder where they went. Thanks

Tab Mix Plusのセッションファイルをインポートするのは可能でしょうか？前からはそっちを使っていましたがつい最近動作がおかしくなりこちらに移行するのを決めましたけど、今Tab Mix Plusではなぜか保存してるタブの1割程度しか復元できない状態ですから、もし変換が可能ならぜひ試してみたいです。
ちなみにブラウザはWaterfox使っています。
不慣れな日本語ですみません。