Check Firefox Cookie Settings

  1. 1

    Open Firefox Settings → Privacy & Security

    Click the three horizontal lines (hamburger menu) in the top right → Settings. Click Privacy & Security in the left sidebar.

  2. 2

    Check the Enhanced Tracking Protection setting

    At the top of Privacy & Security, Firefox shows your protection level: Standard, Strict, or Custom. Strict mode blocks some cookies that Standard does not — if a site is not working, try switching to Standard temporarily. Click Standard and reload the page.

  3. 3

    Scroll to Cookies and Site Data

    Ensure “Delete cookies and site data when Firefox is closed” is unchecked. If this is checked, Firefox deletes all cookies every time you close it — this logs you out of all sites and is the most common reason cookies seem not to work.

Allow Cookies for a Specific Site

  1. 4

    Add the site to exceptions

    In Privacy & Security → Cookies and Site Data → click Manage Exceptions. Type the website address (e.g. https://example.com) and click Allow. Click Save Changes. This site will always be allowed to set cookies regardless of your general privacy settings.

Clear Existing Cookies for a Fresh Start

If a site is behaving oddly: Privacy & Security → Cookies and Site Data → Manage Data → search for the site domain → Remove Selected. This clears just that site’s cookies and forces a fresh login, often resolving issues with stuck login states or broken sessions.

Firefox Enhanced Tracking Protection and cookiesFirefox’s ETP blocks cross-site tracking cookies by default (third-party cookies from advertisers and trackers). This is good for privacy and should stay on. What you are enabling when troubleshooting is first-party cookies from the site you are visiting — these are essential for logins and shopping carts and are not blocked by default in Standard mode.

Frequently Asked Questions

Almost always because “Delete cookies and site data when Firefox is closed” is enabled (Privacy & Security → Cookies and Site Data). Disable this setting. Alternatively, Firefox may be set to clear history on close (Privacy & Security → History → Custom settings → Clear history when Firefox closes). Ensure Cookies is unchecked in the what-to-clear list.
Yes — Firefox’s Enhanced Tracking Protection blocks many third-party tracking cookies by default that Chrome allows. This makes Firefox more private out of the box. In Strict mode, Firefox also blocks some social media trackers and fingerprinting scripts that Standard mode allows. This occasionally breaks sites that rely on third-party functionality — switching to Standard mode or adding a site exception resolves most cases.