Is it possible to create a Firefox shortcut with username and password stored inside? Even if the cookies got cleared the username and password should remain.
WARNING: this method is insecure since bookmarks are not encrypted, which means anyone with access to your machine could login with your credentials if you save bookmarks this way.
Most web browsers support the following syntax:
Using this syntax will work in a Firefox bookmark (though FF will warn you when you click it)
Note that this only works for websites that use HTTP password authentication (.htpasswd files in Apache). This won't work, for example, on Facebook.
Get Secure Login extension. It allows to store bookmarks with login data (you need to enable that option in the extension preferences). It is secure, because it doesn't store the password or the user in the bookmark url, but just the reference to the Secure Login data, which is retrieved from the password manager and thus can be protected with a Master Password, which is highly recommended btw.