Firefox can remember what you've entered in forms on web pages, also known as text fields. After you've entered something into a form on a web page (such as a search box), the next time you visit that page, your previous entry should be available to re-use. If you find that you can't re-use your form entries, follow the instructions in this article.
If you find that Firefox will save form entries for forms on only some websites, but not on others, the site might be telling Firefox to not save form history. This is especially common on email and banking websites.
If you find that Firefox will not save any text you enter into forms, follow the instructions below.
Make sure that Firefox is set to remember form entries and that saved form entries are not being automatically cleared:
If either of those options were not set properly, setting them as above should enable form autocomplete.
If you find that Firefox's settings were correct, but autocomplete still doesn't work on any forms, check for conflicting extensions:
Click the menu button and choose Add-ons. The Add-ons Manager tab will open.
If a conflicting extension was present, form autocomplete should work again after disabling it and starting Firefox again.
Some Internet security software (including antivirus, antispyware, firewall, and privacy programs) will clear Firefox's form history. Check the settings for these programs if you have one or more of them.