How did you uninstall Firefox? Pin tabs and anything else will be gone if you uninstall Firefox if you didn't do the backup Firefox FAQ to restore the data back there's nothing much that can be done here.

Pinned tabs are stored in sessionstore.jsonlz4 in the Firefox profile folder, so you would need a backup copy of a sessionstore file that has those pinned tabs. Pinned tabs aren't part of Sync, so it is not possible to restore them that way.

You will normally find these files in the sessionstore-backups folder:

• previous.jsonlz4 (cleanBackup: copy of sessionstore.jsonlz4 from previous session that was loaded successfully)
• recovery.jsonlz4 (latest version of sessionstore.jsonlz4 written during runtime)
• recovery.baklz4 (previous version of sessionstore.jsonlz4 written during runtime)
• upgrade.jsonlz4-<build_id> (backup created during an upgrade of Firefox)

You can copy a file from the sessionstore-backups folder to the main profile and rename the file to sessionstore.jsonlz4 to replace the current file with Firefox closed.

• make sure to backup the current sessionstore.jsonlz4
• https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data

You can look at this tool to inspect a compressed jsonlz4 sessionstore file. This tool works locally, no uploading done.

• https://www.jeffersonscher.com/res/scrounger.html

Hi cor-el,

I completely uninstalled Firefox without making backups so am afraid I lost all tabs.

Cheers,

Ricardo