How to Recover Your Firefox Session When All Hope is Lost

Last week my house had some electrical issues, and our landlord came round to take a look at things. During this time, my computer got turned off without warning when a fuse was removed. It recovered fine, but next time I went to shut down in a hurry, Firefox was hanging around, and I wanted it dead. I chose to kill it and shut down—a mistake I would soon regret.

When the fuse and power were restored and my machine booted up again, I opened Firefox. It asked to do a session restore, as it had closed down with an error. That’s fine, no problem; I did force quit and the restore has always worked. Not this time. It DID load all my open tabs, probably about 100-130 or so… every single one of them… blank, with no URL. I don’t have all those tabs open at once, but in one session—most of which is stored in Firefox’s grouped tabs feature.

Many hours had gone into collecting those tabs. Several of them were tabs of projects put on pause, a few article resources, plans for future projects, random research and reading I wanted to finish at some time. All lost. I was under the false impression that Firefox by default stored several sessions, but sadly it does not. This can be achieved with a plugin which I’ll get to later.

I had a frantic panic and it took about half an hour to sink in that I’d probably never see those tabs again. Because I’d spent so many hours gathering them, however, I decided I’d try and get them back, somehow. I figured the data must be stored somewhere, and maybe Firefox just wasn’t loading the URLs because the file was corrupt.

After a bit of poking around and Googling, I found the profile data is stored in the appdata folder (%APPDATA%\Roaming\Mozilla\Firefox\Profiles\[RandomNumber]) on Windows (you may or may not have the “Roaming” folder). If you’re a Mac user, you should find the profile data at ~/Library/Mozilla/Firefox/Profiles/ or ~/Library/Application Support/Firefox/Profiles/. The files you’ll be looking for is sessionstore.js and sessionstore.bak. Firefox automatically creates a backup encase of crashes, but if like me, you opened and closed Firefox several times before realising this, you will have overwritten both these files several times.

At this point, I almost gave up. I figured the chances of recovering the session data file was pretty low. Having successfully used file-recovery software before, I decided to give it a shot. On Windows I use Recuva, made by the same people as CCleaner, and it’s free. If you’re on a Mac and you don’t have Time Machine or (for whatever reason) don’t have any form of backup enabled, you can have a look at some Mac-based alternatives.

Now I knew what file I was looking for, where it was, and how to recover it. Because of the way the NTFS file system works on Windows, when you delete a file (from the recycle bin), you actually just delete the index to the file, allowing that space to be reused. Recuva knows this, and searches for un-indexed files on the drive. It sometimes only recovers partial files, but I was lucky enough to find a completely untouched version of my sessions file.

After the file was recovered, I moved it to the correct location and re-opened Firefox. JOY! After the huge worry, I decided to installed Session Manager, a Firefox plugin which allows some clever session management features, like backing up x number of previous sessions, something I thought was already in place.

If you have had a similar horrible Firefox (or other browser-related) experience, let us know in the comments below.