Cannot Log In to Facebook in Firefox

Facebook login can fail in Firefox for a few common reasons: corrupted facebook.com cookies, Strict Enhanced Tracking Protection blocking third-party cookies, a privacy or ad-blocking extension, or an outdated Firefox build.

Work through the fixes in order, from clearing Facebook's site data and adjusting privacy settings to disabling extensions and resetting Firefox. You can get back into your account without losing bookmarks or saved passwords.

In this guide, I have covered:

Why You Cannot Log In to Facebook in Firefox

You typed your password, clicked Log In, and Facebook either refreshed the page or asked you to log in again. That usually means Firefox is blocking a cookie or script Facebook needs, or it is holding onto a stale facebook.com cookie.

The usual suspects are an outdated Firefox build, Strict Enhanced Tracking Protection, a privacy or ad-blocking extension, and leftover data from an earlier Facebook session. Work through the fixes in the order they appear, quickest first.

Update Firefox First

If Firefox has not been updated in a while, you may be running a build with a login or cookie bug that Mozilla has already fixed.

1. Open the Firefox browser app on your computer.
2. Click on the More menu and select the Settings menu.
   
3. Scroll down to the Firefox Updates section within the General tab, and click the Check for updates button.
   
4. Firefox will check for updates and download them. It may ask to restart to complete the installation of the update.
   The browser will be updated to the latest version.

After Firefox restarts, try signing in to Facebook again. If the same error appears, move to the next fix.

Clear Facebook’s Cookies and Site Data

When you click Log In but Firefox only refreshes the page or shows a “session expired” error, a corrupted cookie for facebook.com is often the cause. Clearing only Facebook’s data is faster than wiping everything.

1. Open facebook.com in Firefox.
2. Click the padlock or icon to the left of the address bar.
3. Click Clear permissions and data for this site at the bottom of the panel, then confirm the dialog.
4. Reload facebook.com and sign in again.

Restart Firefox, open facebook.com, and try logging in again. If login works, you can re-enable any previously disabled extensions one at a time to find the culprit.

Clear All Cookies and Cached Web Content

If clearing only Facebook’s data does not help, the cached web content used during login (images, scripts, session tokens) may be corrupted. Clearing everything gives Firefox a clean slate, and the full cleanup steps are in Clear Browser Cookies and Cache from the Mozilla Firefox.

1. Open the Firefox browser on your computer.
2. Click on the More menu and select the Settings menu.
   
3. Switch to the Privacy & Security tab and scroll to the Cookies and Site data section.
   
4. Click on the Clear Data... button.
5. Enable the checkbox for the 'Cookies and Site Data' and 'Cached Web Content' options.
   
6. Hit on the Clear option.
   It will immediately delete the cache, cookies, and site data on the browser.

You will be signed out of every site at once. Reopen facebook.com and log in with your email or phone and password. If you also want to wipe your browsing history at the same time, see Clear Browsing History from Mozilla Firefox.

Disable Browser Extensions

If Firefox only fails on Facebook while other sites log in fine, an add-on is likely interfering. Ad blockers and privacy extensions sometimes stop Facebook’s login scripts or delete the cookie Facebook sets during sign-in.

1. Click the hamburger menu and select Add-ons and themes.
2. In the left sidebar, click Extensions.
3. Use the blue toggle next to each extension to disable it. Start with ad blockers, tab managers, and any extension you installed in the past few weeks.
4. Restart Firefox from the hamburger menu .
5. Use Firefox normally for a few minutes, then check about:performance. If usage dropped sharply, re-enable extensions one by one to find the offender.

With extensions disabled, try logging into Facebook again. If it works, turn extensions back on one at a time until the problem returns. Keep that one disabled or find a replacement.

Privacy Badger, uBlock Origin, NoScript, and similar extensions are the most common offenders on Facebook’s login page.

TIP: Open a private window with Ctrl+Shift+P (or Cmd+Shift+P on macOS) and try Facebook there first. A private window uses no saved cookies and disables most extensions, so it is a fast way to confirm whether the issue is in your profile.

Set Enhanced Tracking Protection to Standard

If you use Firefox’s Strict privacy mode, Facebook’s login page may reload endlessly, hang on a spinner, or show a “cookies are blocked” message. Strict mode blocks third-party cookies that Facebook needs during sign-in.

1. Click the hamburger menu at the top right and choose Settings.
2. Select Privacy & Security on the left.
3. In the Enhanced Tracking Protection section, pick Standard.
4. Sign in to Facebook and check whether the loop is gone.

Reload facebook.com and try again. If Standard mode fixes it but you want stricter blocking elsewhere, switch to Custom later and allow third-party cookies only for facebook.com.

Try Firefox Troubleshoot Mode

If Facebook still refuses to log you in, Troubleshoot Mode gives you a clean Firefox session without any extensions, themes, or custom settings. Use it to test whether the problem lives in your profile or in Firefox itself.

1. Click the hamburger menu at the top right of Firefox.
2. Click Help.
3. Select Troubleshoot Mode….
4. Click Restart in the confirmation dialog.

Once Firefox restarts in Troubleshoot Mode, try Facebook again. If login works there, an add-on or setting in your normal profile is the cause. If it still fails, continue to the next fix.

Sign Out of Facebook Everywhere and Sign Back In

If your account is open on another phone, tablet, or browser, a stale session token can make Firefox reject a new login. Signing out everywhere clears that conflict.

1. Open facebook.com in Firefox.
2. Click your profile picture at the top right and choose Log Out.
3. Quit Firefox: click the hamburger menu at the top right, then select Exit on Windows/Linux or Quit Firefox on macOS.
4. Reopen Firefox, go back to facebook.com, and sign in with your normal password.
5. If Facebook offers Save Browser or This Was Me on the security check, click it to confirm the new session.

After you sign out of all sessions, return to Firefox and log in fresh. Saved passwords in Firefox still autofill the login form, so you do not need to retype anything.

Refresh Firefox

If all else fails, Refresh Firefox resets preferences, removes extensions and themes, and clears site data. Your bookmarks, saved passwords, and history stay put. For the full reset walkthrough, see Reset Mozilla Firefox Browser Settings on the Computer or Mozilla’s Refresh Firefox support page.

1. Click the hamburger menu , choose Help, then select More Troubleshooting Information.
2. On the Troubleshooting Information page, find the Give Firefox a Tune Up section on the right.
3. Click Refresh Firefox and confirm by clicking Refresh Firefox in the dialog.
4. Wait for Firefox to restart. Your bookmarks and logins are preserved, but extensions and most site settings are reset.

After Firefox restarts, open facebook.com and try once more. Reinstall only the extensions you actually use.

RELATED: Clear Browser Cookies and Cache from the Mozilla Firefox