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how to restore the previous session

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  • 61 views
  • Last reply by wenjuan1980

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Hello, I know when I closed the firefox browser , I can reopen firefox browser and click "settings"-- " history" --" Restore previous session" to retrieve all the webpages I was viewing last time. but this time it seems I made a mistake . I closed the firefox browser in the beginning with many valuable webpage still opened, after I restart the firefox browser, I close the browser by accident without firstly reloading all the restore previous session . Then I have to open firefox brower again, and try to click "settings"-- " history" --" Restore previous session" to try to retrieve all the webpages I was viewing in the first time. but this time no previous session can be loaded. since those webpages I was viewing are important webpage I need to check, May someone tell me how to get those valuable webpage link again? I know I can try to find those webpage link slowly by checking all the history day by day. but honestly speaking, I have 15 around webpages in the firefox brower and some of them are viewed around 20 days or 30 days before . I haven't closed my firefox browser for almost 40 days so it will be very hard for me to search the history webpage to find out them one by one. I am not sure whether there are some tips to try to load the "restore previous session " again for the first firefox browser I closed.

Hello, I know when I closed the firefox browser , I can reopen firefox browser and click "settings"-- " history" --" Restore previous session" to retrieve all the webpages I was viewing last time. but this time it seems I made a mistake . I closed the firefox browser in the beginning with many valuable webpage still opened, after I restart the firefox browser, I close the browser by accident without firstly reloading all the restore previous session . Then I have to open firefox brower again, and try to click "settings"-- " history" --" Restore previous session" to try to retrieve all the webpages I was viewing in the first time. but this time no previous session can be loaded. since those webpages I was viewing are important webpage I need to check, May someone tell me how to get those valuable webpage link again? I know I can try to find those webpage link slowly by checking all the history day by day. but honestly speaking, I have 15 around webpages in the firefox brower and some of them are viewed around 20 days or 30 days before . I haven't closed my firefox browser for almost 40 days so it will be very hard for me to search the history webpage to find out them one by one. I am not sure whether there are some tips to try to load the "restore previous session " again for the first firefox browser I closed.

Chosen solution

Can you reopen closed windows (History -> Recently Closed Windows) ?

Do you have a recent upgrade.jsonlz4-<build_id> in the sessionstore-backups folder in the Firefox profile folder?

You can use the button on the "Help -> More Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page (Root directory).


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 look at this tool to inspect a compressed jsonlz4 sessionstore file.

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Chosen Solution

Can you reopen closed windows (History -> Recently Closed Windows) ?

Do you have a recent upgrade.jsonlz4-<build_id> in the sessionstore-backups folder in the Firefox profile folder?

You can use the button on the "Help -> More Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page (Root directory).


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 look at this tool to inspect a compressed jsonlz4 sessionstore file.

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Hi Cor-EL, No language can describe my appreciation to you . I followed your instruction, and found out the sessionstore-bakups folder. I successfully use one of the old backup file in the folder to reload the important webpages I need in firefox browser. Thank you so much . Your feedback really helps !