Fix Firefox Autofill Still Working After Disabling It

Firefox may keep inserting saved addresses, payment details, or passwords after you turn off the relevant autofill option. Form filling and saved logins are separate settings, so you have to switch off each one that applies.

Start in Firefox's Privacy & Security settings, then test on a fresh form. If fields still fill themselves, check extensions and the Config Editor before you assume the toggle failed.

In this guide, I have covered:

Why Firefox still fills forms after you turn autofill off

You switched autofill off, and an address or card number still lands in the first field you click. Firefox keeps form filling and saved logins under separate controls, so turning one off leaves the others running.

Start with the two form switches in Settings. If you want the official wording, Mozilla’s support thread on controlling automatic form filling in Firefox covers the same controls.

1. Open the menu.
2. Select Settings.
3. Select Privacy & Security.
4. Scroll to Forms and Autofill.
5. Turn off Autofill addresses.
6. Turn off Autofill credit cards.

Turning autofill off does not clear text already sitting in an open form. Select the inserted text and delete it by hand before you reuse that page.

Close the page and open a fresh form. You’ll know it worked when the address and payment fields stay empty until you type in them.

Turn off login autofill separately

A username or password still appears the moment a login page loads. That is a different switch from addresses and cards, and it stays on until you turn it off.

1. Return to Privacy & Security in Settings.
2. Scroll to Passwords.
3. Turn off Save and autofill logins or Autofill logins, depending on the label shown.
4. Close and reopen the affected website.
5. Open a new login form and check whether Firefox inserts a stored username or password.

TIP: You do not have to delete saved passwords to stop automatic filling. Turn off the login autofill control and your logins stay in Firefox, ready to manage later.

Open the site again in a new tab and check the login form. You’ll know it worked when both the username and password fields stay empty.

Check extensions that fill forms for you

The filling only happens on certain sites, and Firefox’s own settings look clean. An extension that fills forms can do this without touching any Firefox switch.

1. Open the menu.
2. Select Add-ons and Themes.
3. Select Extensions.
4. Review extensions related to forms, autofill, passwords, addresses, or shopping.
5. Temporarily turn off any extension that could fill the affected fields.
6. Reopen the affected website in a new tab.

Reopen the site you were testing. You’ll know it worked when the fields stay blank with the extension switched off. If the text is gone, leave the extension disabled, or open its own options and look for a form-filling setting before you enable it again.

Confirm the form autofill preference is off

The settings pages look right, yet something still fills in. The Config Editor shows whether the main form autofill preference is actually off, which helps when a change does not seem to stick. A toggle that will not hold is not unique to autofill: the same logic drives fixes for a desktop site toggle that will not stick in Firefox.

1. Open the menu.
2. Select Settings.
3. Select General.
4. Scroll to the bottom of the page.
5. Select Config Editor.
6. Accept the warning about entering advanced configuration.
7. Search for browser.formautofill.enabled.
8. Set browser.formautofill.enabled to false.
9. Close the Advanced Configuration tab and restart Firefox.

After Firefox restarts, open a new form. The value for browser.formautofill.enabled should still read false, and Firefox should not insert form data on its own.

RELATED: Reset Mozilla Firefox Browser Settings on the Computer

Run a final test on a real form

You want proof, not a hunch. Pick a form with the same kinds of fields Firefox was filling before, because Firefox may only complete fields it recognizes.

1. Open a new tab on the affected website.
2. Open a form that includes a name, address, payment, or login field.
3. Do not click any field in the form.
4. Wait for the page to load completely.
5. Confirm that Firefox does not fill the fields automatically.
6. Type into the form manually and submit it if necessary.

Fields that stay blank without you touching anything mean the automatic filling has stopped. If one field still fills, work out whether it holds an address, a card number, or a login, then go back to that setting or extension.