How to AutoFill Passwords in Mozilla Firefox

A password manager creates and fills strong passwords for you in Mozilla Firefox

What is AutoFill?

AutoFill gives you the option to save your passwords, addresses, and payment cards so that the browser or other service can fill in forms for you. Rather than typing the same information over and over when you’re registering for a new account or buying something, AutoFill enters those details for you in just a few clicks. The Mozilla Firefox browser offers a built-in AutoFill, and password managers like LastPass also offer AutoFill along with extra features and security.

Why use AutoFill on Mozilla Firefox?

Store personal information icon

Save time

Similar to Firefox autocomplete, LastPass AutoFill eliminates time spent on typing repetitive information. By filling it in for you in a few clicks, you’ll be able to complete tasks much more quickly.

Autofill online forms icon

Reduce headaches

It’s hard to remember dozens, or even hundreds, of username and password combinations. With the AutoFill feature, you store the right information once, and it’s filled for you correctly, every time.

password sharing icon

Improve security

If you must remember and type all your passwords, you’ll choose ones that are simple and insecure. With a password manager to remember and AutoFill your credentials, you can create strong, unique passwords, too.

What can LastPass AutoFill on Mozilla Firefox?

Usernames and passwords

Once your passwords are stored with LastPass — autofill will save you from typing another password ever again. Automatically log in to saved sites and auto-save newly created accounts.


Whether you’re shipping to the office or to your home, LastPass saves all your addresses so you can finish shopping quickly.

Payment cards and credit cards

When you’re ready to make a purchase, LastPass makes it easy to complete your payment and go on to the next thing.

How a password manager works with AutoFill

Many people choose a password manager like LastPass for the added security and flexibility. Once you download the LastPass extension from the Firefox Add-Ons Store, it integrates directly with Firefox. Whenever you log in to an account on a website, LastPass will ask to save the username and password. When you return to the site, LastPass will autocomplete the login for you! LastPass can also save and fill addresses payment or credit cards, and even generate new passwords when you’re registering on a new website.

Getting started with LastPass for Mozilla Firefox

Step-by-step guide on how to start autofilling with LastPass

  1. Go to and click the option to Get LastPass Free
  2. Create a LastPass account, with a master password – the last password you’ll need to remember
  3. When prompted, download the LastPass addon to Firefox
  4. Ensure the extension is red, meaning you’re logged in to your new LastPass account
  5. Keep browsing the way you did before. Now, LastPass will ask to save passwords, fill logins, generate passwords, and more

Cross-platform password management

Download and use LastPass across any combination of our supported browsers and devices.


Google Chrome

Get LastPass Chrome for the most robust feature set of any password manager option.



Access your personal data on the go with LastPass for Android. Browser and in-app autofill allow for a seamless mobile experience.



Keep your accounts at your fingertips with LastPass for iPhone. Our iOS app now supports in-app autofill for one-touch login.



View, edit, and manage your LastPass Vault from your desktop with our Mac App.



Manage your logins and personal data in your LastPass Vault directly from your Windows computer.


Mozilla Firefox

Secure one-click login with our Firefox extension.


Apple Safari

Save keystrokes and stay secure online with our Safari password manager.


Microsoft Edge

Never type another password in your browser with LastPass Microsoft Edge extension.


Opera Browser

Streamlined access to your favorite accounts and save time at checkout with LastPass for Opera.


And many more

View the full list of compatible LastPass browsers and devices here.

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