This extension takes a snapshot of open tabs every 15 minutes or so for the past 3 hours. If you exit the browser the most recent 10 snapshots are saved, so when you open the browser later, they can be quickly restored. I found this to be very useful.

Works exactly as it says for us "tab hoarders"
Thank you Kevin

After trying several add-ons over the years to backup tabs for the occasional (but inevitable) loss of all tabs, this one is the only one that worked and recover all my tabs flawlessly. Many thanks to the developer(s).

Loss of tabs seems to happen for me when clearing all history manually and closing FF right after. Sessionstore backup is gone the moment you reopen FF and discover your tabs are gone.

This add-on might not work for every crash, but it works for this one, which I have once or twice a year.

For worse situations (I never had a corrupt FF folder), I resort to ~monthly manual backups of the FF folder - you just wouldn't recover your most recent tabs.

Suggestion : the choice offered between 1) replace all current tabs by the backup or 2) open the backup session tabs in a new window is really great and well thought !
A convenient 3rd option would be to add the tabs to the current window instead of a to a new window (yet hardly a must have).

Great for me, it does the job.

One comment thought, I think the datetime format used for the filename should be :
2021-01-31T14:00:00+01:00
and not :
2021-01-31-T 14 00 00 +0100

see https://en.wikipedia.org/wiki/ISO_8601
Thanks again anyway

Edit : actually I realise, you cannot have colon (:) inside a filename on Windows, which is a shame, because it's perfectly fine with Linux
But then you could follow the basic (compact) format, also allowed by the ISO standard, which is :
20210131T140000+0100
but it's less easy to read

Cheers

The ONLY Firefox Tabs Exporter I could find that keeps the tabs separated into window groups in the export file. Every other Add-on exports as one single list, which often loses a lot of context.