Firefox cookies keep you signed in, remember site preferences, and preserve carts or account state. Deleting them is a common fix when a site will not stay logged out, shows the wrong cart, or seems stuck on old account information.
Does this affect you?
Use this for Firefox on Windows or Mac when you want to delete cookies for one website or every website. Clearing cookies signs you out of affected sites, but it does not delete saved passwords, bookmarks, or downloaded files.
Delete all cookies in Firefox
This resets website cookie state across the browser.
- Click the Firefox menu button.
- Open Settings.
- Choose Privacy & Security.
- Scroll to Cookies and Site Data.
- Click Clear Data.
- Check Cookies and Site Data.
- Uncheck Cached Web Content if you want to keep cache.
- Click Clear, then confirm with Clear Now.
Delete cookies for just one site
Use this when one site is the only problem.
- Open Settings > Privacy & Security.
- Under Cookies and Site Data, click Manage Data.
- Search for the site name.
- Select the site.
- Click Remove Selected.
- Click Save Changes.
Delete a site cookies from the address bar
Firefox can also clear the current site directly from the page.
- Visit the site.
- Click the lock or shield icon near the left side of the address bar.
- Choose Clear cookies and site data, or open the permissions area if your Firefox version places it there.
- Confirm, then reload the page.
More control
Clear cookies automatically on close
Open Settings > Privacy & Security. Under History, choose Use custom settings for history, enable Clear history when Firefox closes, then open Settings beside it and make sure Cookies is selected.
Keep selected sites signed in
If automatic clearing is enabled, use Manage Exceptions under Cookies and Site Data. Add sites such as email or banking and choose Allow so Firefox keeps their cookies.
Use a Private Window for temporary browsing
If you only want a clean temporary session, open a Private Window with Ctrl+Shift+P on Windows or Cmd+Shift+P on Mac. Cookies from that session disappear when the private window closes.
Sources
- Mozilla Support – Clear cookies and site data in Firefox (2025)
- Mozilla Support – Enhanced Tracking Protection in Firefox for desktop (2025)
- Mozilla Support – Delete cookies to remove the information websites have stored on your computer (2025)