You need a backup copy of logins.json (encrypted logins) and possibly key4.db (encryption key and primary password) to be able to recover lost logins. If you recently accidentally cleared all logins then you may have a logins-backup.json file that Firefox creates when you add or edit logins to be able to undo the latest changes. To make Firefox to use the backup you need to copy logins-backup.json to logins.json to replace the current logins.json with Firefox closed. You can look a utility to browse System Restore points to see if you can locate a suitable logins.json. *https://www.shadowexplorer.com/ *https://www.nirsoft.net/utils/shadow_copy_view.html Make sure you keep a backup copy of logins.json and logins-backup.json and key4.db. 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 <b>about:profiles</b> page (Root directory). *Help -> More Troubleshooting Information -> Profile Folder/Directory:<br>Windows: Open Folder; Linux: Open Directory; Mac: Show in Finder *https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data