Firefox SessionStore and Tabs
Jump to navigation Jump to search

Opening Browser Tabs that were previously open has become a nice luxury. But what happens when something goes wrong?

Based on information from these sites;

To locate the Profile Folder, in the Firefox Address Bar type: about:support (note, some references state it is in the ...Local Folder, other state it is in the ...Roaming Folder)

  • Typically here: C:\Users\YourUserNameHere\AppData\Roaming\Mozilla\Firefox\Profiles

To restore sessions;

  • Look in the ...sessionstore-backup Folder, find the most recent file ending in .jsonlz4 (thankfully the file name won't begin with sessionstore..., and should begin with 'previous' or 'recovery')
  • Copy it somewhere like the Desktop
  • Close Firefox
  • copy it to the main profile directory (where the session-backup Folder is), rename it to sessionstore.jsonlz4
  • ...should be good to go.


  • Mozilla / Firefox Documentation indicates there is a .../sessionstore.jsonlz4 File stored in a profile. From direct observation, I can say that this isn't necessarily true. And beyond that, I've copied a backup of a sessionstore.jsonlz4 file to the appropriate location, opened Firefox, had it restore all the tabs properly, and then the sessionstore.jsonlz4 file disappears. WTF? It does make new backups in the .../sessionstore-backups Folder though.