Websites remembering you and automatically log you on is stored in a cookie. * Create an allow cookie exception (Tools > Options > Privacy > Cookies: Exceptions) to keep such a cookie, especially for secure websites and if cookies expire when Firefox is closed. Make sure that you do not run Firefox in Private Browsing mode. * https://support.mozilla.com/kb/Private+Browsing Do not use Clear Recent History to clear the "Site Preferences" and the "Cookies" as this doesn't take exceptions into account, but removes all specified data, so you lose the cookie that makes the website remember you. * https://support.mozilla.com/kb/Clear+Recent+History Clearing "Site Preferences" clears all exceptions for cookies, images, pop-up windows, software installation, and passwords.