Have you read this: Autofill logins on Firefox https://support.mozilla.org/en-US/kb/autofill-logins-firefox

Are you talking about saving the username and password in the Password Manager or about the website remembering you, so you do not need to login on each visit ? Detail like websites remembering you and log you in automatically is stored in cookies, so make sure you aren't clearing important cookies. You can use these steps to make a website recognize and remember you. *create a cookie allow exception with the proper protocol (https:// or http://) to make a website remember you You can check that you aren't clearing important cookies. *using "Delete cookies and site data when Firefox is closed" keeps cookies with an allow exception *using "Clear history when Firefox closes" to clear cookies clears all cookies including cookies with an allow exception you may want to keep *clearing "Site Preferences" clears exceptions for cookies, images, pop-up windows, and software installation and exceptions for passwords and other website specific data *Settings -> Privacy & Security<br>Cookies and Site Data: "Manage Exceptions" *Settings -> Privacy & Security<br>Firefox will: "Use custom settings for history":<br>[X] "Clear history when Firefox closes" -> Settings ---- *https://support.mozilla.org/en-US/kb/fix-login-issues-on-websites-require-passwords *https://support.mozilla.org/en-US/kb/delete-browsing-search-download-history-firefox