You can remove all saved passwords in the Password Manager *Tools > Options > Security: Passwords: "Saved Passwords" > "Show Passwords" *https://support.mozilla.org/kb/make-firefox-remember-usernames-and-passwords ---- You can also use Clear Recent History to clear the saved passwords and maybe the form data as well when you close Firefox.<br /> Form data can also be cleared during a session via History > Clear Recent History. *https://support.mozilla.org/kb/Clear+Recent+History