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My Windows XP system crashed. Usually about:sessionrestore shows me my previous session. But this time, after I rebooted, the page appeared blank.

I was able to find my sessionsstore files in my profile folder. They have names like sessionstore-1.js through sessionstore-8.js. There is also a sessionstore.bak, which was probably created when the system crashed. I don't trust the sessionstore.bak: it's really small in size.

Can I use sessionstore-8.js instead to get back my old sessions?

Also, how exactly do I go about this? Should I quit Firefox before making any changes under the profile directory?

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Check out this blog post for restoring information from sessionstore.bak otherwise just open the sessionstore-#.js in a text editor or check this out. +1 though, interesting question – Raystafarian Feb 28 '12 at 11:42
The above mentioned methods for extracting URLs from sessionstore-#.js extract ALL URLs including each tab's browsing history. (not what anyone wants, I think) – Mark Jeronimus Mar 26 '12 at 8:31

I know this post is rather old, but I have encountered the same problem and didn't find any good solution to restore the sessionstore.bak file. Here is the solution that worked for me:

Assuming that your sessionstore.json (seamonkey) or sessionstore.js (firefox) is rather empty and you lost all your tabs. Assuming that your sessionstore.bak file is bigger and contains all your tabs, but simply renaming sessionstore.bak to sessionstore.json (or .js) doesn't work.

Here is how to restore all your tabs using the "sessionstore.bak" file:

  1. Close the browser, make a backup of the sessionstore.bak file and don't relaunch the browser, it would overwrite the file.
  2. Copy sessionstore.bak file to sessionstore.json (or .js for firefox).
  3. Edit the sessionstore.json file with a decent editor that doesn't cut long lines (the file is a 1 line JSON file that can contain several MB of data!). I have used vi successfully.
  4. At the beginning of the file, you will see something like this:


    Simply replace this line by this (basically we remove the selectedWindow and _closedWindows fields):


    (with vi editor, just place the cursor after the first opening square bracket, then hit [SUPPR] the required number of times, then hit [:] [w] [q] [ENTER])

  5. Open your browser, and now all the tabs should appear as before :-)

Hope this helps, this is a "works for me" solution!

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I know this is old - but just in case someone comes upon this. You can use the utility at to restore your tabs. Just paste in the contents of sessionstore.bak.

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This page has failed with several of my files. A big lack of this page is that it does not say what it is supposed to do. – Nicolas Barbulesco Oct 5 '13 at 8:03
Can you provide the data on which it failed? – Johnny Oct 6 '13 at 13:36
I have over 100 urls in my sessionstore.bak. The website only appears to display about 15 of them. – Rucent88 Apr 5 '14 at 4:07
hi @Rucent88, is there any chance you could provide me with the file so I can see what's going wrong? – Johnny May 28 '14 at 21:07

see if this helps any: remove numbered sessionstore-##.js files (sessionstore-1.js).

Those shouldn't be there and usually indicate that other software is accessing the main sessionstore.js file that Firefox rewrites every 10 seconds.

  • copy sessionstore.bak in the profile folder,rename it to .js replace the cache folders moved in the "recovered files" directory back in their original location replace a couple of missing userchrome.css files with some others from a previous backup delete that sessionstore-1.js
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How is removing the sessionstore-##.js files supposed to help the OP, when he wants to restore the session from one of those files? – Dmitry Grigoryev Oct 2 '15 at 19:00

EDIT removed links as the destination URL has moved (and there was too much to copy into this answer).

So, as a quick answer, try sessionstore.js in your Profile folder.

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Open the most recent file (probably sessionstore.js) in an advanced text editor supporting RegEx Search & Replace (eg. Textpad, Notepad++).

Replace all "entries":\[{"url":"([^"]*)" With \n\1\n

and the url's of the last opened tabs will appear on every other line.

[Note on textpad: you need to enable POSIX syntax in Preferences/Editor.

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