Maybe export the logins to CSV and edit this file. Delete all logins and import the edited CSV file via the about:logins page (Password Manager). *https://support.mozilla.org/en-US/kb/export-login-data-firefox Make sure to keep a backup of logins.json and key4.db. *https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile You need to enable import CSV in the Password Manager (about:logins) via the <b>about:config</b> page as this menu item is currently hidden for performance reasons. *about:config => signon.management.page.fileImport.enabled => true *https://support.mozilla.org/en-US/kb/about-config-editor-firefox Close and restart Firefox to make the Import menu item appear in the gear menu on the about:logins page.