Join the AMA (Ask Me Anything) with the Firefox leadership team to celebrate Firefox 20th anniversary and discuss Firefox’s future on Mozilla Connect. Mark your calendar on Thursday, November 14, 18:00 - 20:00 UTC!

This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Avatar for Username

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Wannan tattunawa ta zama daɗaɗɗiya. Yi sabuwar tambaya idan ka na bukatar taimako.

Lost my previous session with hundreds of tabs across multiple FF windows

  • 1 amsa
  • 0 sa na da wannan matsala
  • 2 views
  • Amsa ta ƙarshe daga cor-el

eugenijuso
eugenijuso
more options

This morning when I turned on my PC, Mozilla didn't restore my previous session across 4 different browser windows. Normally, it restores my session (and the 4 windows) automatically. But this time, it didn't. I opened Mozilla, but the "restore previous session" option didn't generate the previously open windows.

I've lost hundreds of tabs that I had open... is there any way to restore my previous session?

Thanks in advance!

This morning when I turned on my PC, Mozilla didn't restore my previous session across 4 different browser windows. Normally, it restores my session (and the 4 windows) automatically. But this time, it didn't. I opened Mozilla, but the "restore previous session" option didn't generate the previously open windows. I've lost hundreds of tabs that I had open... is there any way to restore my previous session? Thanks in advance!

All Replies (1)

cor-el
cor-el
  • Moderator
  • Top 10 Contributor
more options

Backup the session files in the sessionstore-backups folder in the Firefox profile folder to make sure not to lose possible important session data. Do NOT close Firefox when Firefox is already running.

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

You can try to restore a recent upgrade.jsonlz4-<build_id> when available or use a utility to browse Windows System Restore points to see if you can find a recent sessionstore.jsonlz4 file.

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