This help article will help you troubleshoot your computer and web browser settings when Mozilla Firefox doesn't remember your username and password for sign-in. 

If the Browser Autofill feature is not working when you have asked to have your ID and Password remembered, we have a few things you can try to fix this:

I. Check your Firefox settings to ensure that you're not clearing your browser history upon browser closing.

1. On the Tools menu, click Options. 
2. Click the Privacy tab.
3. Under Firefox will:  ensure the Remember history checkbox is checked.
4. Click OK.

II. Double-check your Autofill settings: 

1. On the Tools menu, select Options. 
2. Click  Security. 
3. Under Passwords, ensure the Remember Passwords for Sites checkbox is checked. 
4. Click OK.

• If Autofill is enabled, click the Exceptions button to see if Yahoo! is on the blocked site list. 

III. Make sure you are at a legitimate Yahoo! sign-in page. 

For security reasons, you should also check to verify that you're on a legitimate Yahoo! sign-in page by looking for the Sign-in Seal. For more information on the Yahoo! Sign-in Seal feature, please see our Using the sign-in seal help page.

For further assistance with Mozilla Firefox, please visit the Mozilla Firefox Help page.