Firefox two-factor authentication is set up on your Mozilla Account, not in the browser’s general settings. Sign in to the account linked to Firefox, open Security, add Two-step authentication, scan the QR code with an authenticator app, then save and confirm a recovery method before finishing.
What Firefox two-factor authentication protects
Mozilla calls the feature two-step authentication. After you enable it, signing in requires your account password plus a one-time code from an authenticator app. Mozilla says this adds protection if someone compromises your password. The setting applies to the Mozilla Account you use with Firefox.
Mozilla’s two-step authentication guide lists authenticator apps including Google Authenticator, Twilio Authy Authenticator, Ente Auth, Zoho OneAuth, Duo Mobile, FreeOTP and KeePassXC. App availability varies by platform.
Enable two-step authentication
- Install an authenticator app on a device you can access during sign-in.
- In Firefox, open the account menu and select Manage account. Alternatively, sign in to your Mozilla Account settings directly.
- Open Security, then select Add beside Two-step authentication.
- Open the authenticator app and scan the QR code on the Mozilla Account page. If you cannot scan it, select Can’t scan code? and enter the displayed secret into the app.
- Enter the one-time code from the app and select Continue.
- Set up a recovery method and complete its confirmation step. Mozilla requires a recovery method before setup is complete.
Choose and save a recovery method
Backup authentication codes
Mozilla provides a set of one-time-use backup authentication codes, each 10 characters long. Download, copy or print the codes, store them somewhere secure, and confirm one when prompted during setup. Each code can be used once. Keep them somewhere accessible even if you lose access to the phone running your authenticator app. See Mozilla’s instructions for backup codes and account recovery.
Crashes, No Sound, or Screen Glitches?
Random freezes, missing sound and display glitches usually trace back to one bad driver. Find and replace yours safely.Free scan · under a minutePC Slower Than It Used to Be?
A free scan shows the junk files, broken settings and background clutter dragging Windows down - then fixes them in one click.Free scan · Windows 10 & 11#1 Best Overall
- POWERFUL SECURITY KEY: The Security Key C NFC is the essential physical passkey for protecting your digital life from phishing attacks. It ensures only you can access your accounts.
- WORKS WITH 1000+ ACCOUNTS: Compatible with Google, Microsoft, and Apple. A single Security Key C NFC secures 100 of your favorite accounts, including email, password managers, and more.
- FAST & CONVENIENT LOGIN: Plug in your Security Key C NFC via USB-C and tap it, or tap it against your phone (NFC) to authenticate. No batteries, no internet connection, and no extra fees required.
- TRUSTED PASSKEY TECHNOLOGY: Uses the latest passkey standards (FIDO2/WebAuthn & FIDO U2F) but does not support One-Time Passwords. For complex needs, check out the YubiKey 5 Series.
- BUILT TO LAST: Made from tough, waterproof, and crush-resistant materials. Manufactured in Sweden and programmed in the USA with the highest security standards.
Recovery phone, if offered
Some eligible accounts may be offered recovery by phone instead of or alongside backup codes. Mozilla describes this as an experimental, progressive rollout initially available to users in the United States and Canada; it sends a one-time password by SMS. If you do not see the option, your account is not currently eligible. SMS can be intercepted or undermined by a SIM swap, so consider that risk when choosing this recovery method. Details are in Mozilla’s recovery-phone guidance.
What to do if a code is rejected
- Check that you selected the authenticator entry for the Mozilla Account you are signing in to.
- Make sure the date and time are accurate on both the authenticator device and the device used to sign in.
- If you use Google Authenticator, open its settings, choose Time correction for codes, then select Sync now.
Mozilla’s troubleshooting steps are in its two-step authentication troubleshooting guide.
Rank #2
- POWERFUL SECURITY KEY: The Security Key NFC is the essential physical passkey for protecting your digital life from phishing attacks. It ensures only you can access your accounts.
- WORKS WITH 1000+ ACCOUNTS: Compatible with Google, Microsoft, and Apple. A single Security Key NFC secures 100 of your favorite accounts, including email, password managers, and more.
- FAST & CONVENIENT LOGIN: Plug in your Security Key NFC via USB-A and tap it, or tap it against your phone (NFC) to authenticate. No batteries, no internet connection, and no extra fees required.
- TRUSTED PASSKEY TECHNOLOGY: Uses the latest passkey standards (FIDO2/WebAuthn & FIDO U2F) but does not support One-Time Passwords. For complex needs, check out the YubiKey 5 Series.
- BUILT TO LAST: Made from tough, waterproof, and crush-resistant materials. Manufactured in Sweden and programmed in the USA with the highest security standards.
If you lose your phone or are locked out
- You are still signed in on another device: Use that session to open Mozilla Account settings and disable two-step authentication.
- You saved a backup code: At sign-in, select Trouble entering code? and enter an unused backup code.
- You set up recovery by phone: Request an SMS code if the recovery-phone option is available for your account.
If you lose access to the authenticator and have neither saved backup codes nor a configured recovery phone, Mozilla warns that you will be locked out of the account and its synced data, including saved passwords, bookmarks and settings. Mozilla’s account access steps are described in the troubleshooting guide.
Move two-step authentication to a new phone
- Disable two-step authentication in Mozilla Account settings.
- Set up the authenticator app on the new phone.
- Enable two-step authentication again and complete the new setup and recovery steps.
- Save the newly issued recovery codes. Re-enabling the feature invalidates all codes from the previous setup.
Use Mozilla’s instructions for disabling two-step authentication as part of the move.
Recommended Free Tools
Rank #3
- Security Key : Protect your online accounts against unauthorized access by using FIDO2 and U2F authentication with T120. It's the world's most protective security key that works with windows, Mac OS, Linux as well as Chrome, Firefox, Edge and many other major browsers.
- Certified with the new FIDO2 standard, T120 provides the benefit of fast login and strong protection against phishing, account takeover as well as many other online attactks.
- Works with : Bank of America, Github, Google, Microsoft, DUO, Twitter, Facebook, Dropbox, Apple, ebay, BINANCE, mor and more.
- Fits USB-C port : Insert the T120 security key into the USB-C port of each service and log in conveniently with one touch
- For the driver download and user guide, please visit TrustKey Solutions Home support page.
Can a passkey replace the authenticator code?
Mozilla says a passkey can satisfy the two-step-authentication requirement during sign-in, so Firefox may not ask for a separate authenticator code. Mozilla still recommends keeping at least one recovery method available.
Quick Recap
Best Value
- Security Key : Protect your online accounts against unauthorized access by using FIDO2 and U2F authentication with T110. It's the world's most protective security key that works with windows, Mac OS, Linux as well as Chrome, Firefox, Edge and many other major browsers.
- Certified with the new FIDO2 standard, T110 provides the benefit of fast login and strong protection against phishing, account takeover as well as many other online attactks.
- Works with : Bank of America, Github, Google, Microsoft, DUO, Twitter, Facebook, Dropbox, Apple, ebay, BINANCE, mor and more.
- Fits USB-A port : Insert the T110 security key into the USB-A port of each service and log in conveniently with one touch
- For the driver download and user guide, please visit TrustKey Solutions Home support page.
Rank #4
- Ultra-Compact FIDO2 Security Key - Plug-and-stay or carry on a keychain. This USB-A hardware security key offers portable, always-on protection for desktop and mobile use. (Item Size: 0.75 X 0.74 IN x 0.25 IN)
- USB-A Hardware Key for All Devices - Works with USB-A ports on PC, Mac, Android, and other laptop/notebook device. Enables secure, cross-platform login with FIDO2.0 passkey support.
- FIDO Certified Security Key - Meets FIDO and FIDO2 standards. Works with Google, Microsoft, GitHub, Dropbox, and more. Please check service compatibility before purchase.
- Passwordless Login with Passkey - Supports passkey login via WebAuthn and CTAP2. Enjoy password-free sign-ins where supported. Not all websites or services currently support passkeys.
- Advanced Multi-Factor Authentication - Offers 200 FIDO2 passkey slots and 50 OATH-TOTP slots. Strong, flexible 2FA/MFA support across various apps and authentication platforms.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
