By default Mozilla Firefox automatically requests to store user names and passwords for websites using the Password Manager features. If Firefox doesn't save passwords on your computer, the Password Manager could be off or the website you're attempting to save passwords for may be part of your list of Exceptions, websites for which Firefox won't attempt to save passwords. Additionally, some websites don't support saving passwords.
Enable Password Manager
When you log in to a website that requires a user name and password, Mozilla Firefox automatically requests to save the password in the Password Manager. If the Password Manager is disabled, Firefox won't request to save the password. Enable the Password Manager by clicking the "Firefox" button, "Options" and then the "Security" tab. Place a check mark next to "Remember passwords for sites."
When Firefox offers to save a password and you decline it the first time, Firefox adds that website to the Exceptions list. The Exceptions list is a list of websites that Firefox won't attempt to save passwords for. Click "Firefox," "Options" and click the "Security" tab and click the "Exceptions" button to view all websites saved to the Exceptions list. If you find a website in the Exceptions list that doesn't belong there, remove it from the list and access the site again to save the password.
Viewing Saved Passwords
Firefox keeps a database of all websites visited and passwords saved to those websites. If you wish to view the password for any of the websites Firefox saved login information for, click "Show Passwords" in the Password Manager. A list of websites appears with your login name and associated password saved in Firefox. Additionally, you can remove single entries in the Password Manager or remove all of the entries using the options at the bottom of the window.
Occasionally you may come across websites that don't support saved passwords. This is often the case for websites that offer online banking services. If the website doesn't support saving passwords, Firefox can't save passwords for the site regardless of the browser options.