How to Block Third-Party Cookies in Chrome and Firefox

If you have ever looked at a pair of trainers online and then seen those same trainers follow you across unrelated websites, you have met third-party cookies at work. The good news is that you can block third-party cookies in a couple of minutes, in both Chrome and Firefox. This guide gives you the steps, explains what changes, and shows how to repair the occasional site that stops working afterwards.

First-party and third-party cookies

A first-party cookie is set by the website you are visiting. It remembers your basket, keeps you logged in or stores your language. Blocking these tends to break sites.

A third-party cookie is set by a different domain embedded in the page, such as an advertising network, a social media button or an analytics provider. Because the same third party can appear on many sites, its cookie can help build a picture of your browsing across the web.

Blocking third-party cookies reduces that cross-site tracking while leaving first-party cookies alone. It is one of the most useful privacy settings available, and it has fairly little downside for everyday browsing.

Why settings differ by version

Browsers have been changing how they handle third-party cookies for several years, and the wording and defaults in the settings menu differ by version. Firefox has long applied tracking protection by default, while Chrome’s approach has evolved and offers a choice of settings. If the menu you see does not match the steps below, search the settings box for “cookies”:.

Block third-party cookies in Chrome

On a computer

1. Open Chrome, click the three dots at the top right and choose Settings.
2. Select Privacy and security, then Third-party cookies.
3. Choose Block third-party cookies. Some versions also offer a milder option that blocks them only in private windows, which is less protective.
4. Close the settings tab. The change applies immediately.

On Android or iPhone

1. Open Chrome, tap the three dots and then Settings.
2. Tap Privacy and security and then Third-party cookies.
3. Select the blocking option.

Chrome on iPhone runs on Apple’s WebKit engine, so a few controls may vary from the Android version.

Block third-party cookies in Firefox

Firefox calls its feature Enhanced Tracking Protection.

1. Open the menu and select Settings, then Privacy & Security.
2. Under Enhanced Tracking Protection, choose a level:
   – Standard blocks known trackers in some contexts, with fewer site problems.
   – Strict blocks more, including cross-site cookies, at the price of occasional breakage.
   – Custom lets you choose exactly what to block, including the cookie type.
3. If you pick Custom, tick Cookies and choose an option such as cross-site tracking cookies or all third-party cookies. Selecting all third-party cookies is the most aggressive.
4. Reload any open tabs.

On Firefox for Android, the same controls are under Settings and then Enhanced Tracking Protection.

What will change after blocking

Most sites will behave normally. You might notice:

• Fewer personalised adverts that follow you around.
• Embedded content from other services, such as some video players, comment widgets or social logins, asking you to sign in again or failing to load.
• Some payment or single sign-on pages working poorly because they rely on cookies from another domain.

Adverts will still appear. Blocking cookies makes them less targeted, not absent.

Fixing a site that breaks

You do not have to give up the setting. Allow exceptions instead.

In Chrome

1. Return to Settings, Privacy and security, Third-party cookies.
2. Find the section for sites allowed to use third-party cookies and select Add.
3. Enter the site address. Chrome offers an option that allows cookies for that site only, rather than everywhere.

You can also click the icon at the left of the address bar when a page is partly blocked, and choose to allow cookies temporarily.

In Firefox

1. Open the site, then click the shield icon in the address bar.
2. Switch off protection for that site, or select the option to view what is blocked.
3. Reload the page.

Firefox remembers exceptions for that site, and you can review the list under Manage Exceptions in the privacy settings.

Only add exceptions for services you trust, such as your bank or an employer’s portal.

Extra steps for better privacy

Blocking third-party cookies is a strong start, but trackers have other methods, including fingerprinting. These habits help:

1. Clear cookies periodically or set the browser to remove them on exit. Our guide to clearing cache and cookies shows how.
2. Review site permissions for location, camera and notifications.
3. Limit extensions to those you need.
4. Decline non-essential cookies when a consent banner appears. UK rules require websites to ask for consent for non-essential cookies, and a “reject all” button should be as easy to find as “accept all”.
5. Consider a privacy-oriented browser if you want stronger defaults. Our browser comparison covers the main choices.

Testing that it worked

Visit a cookie checking page from a reputable privacy organisation, or open your browser’s developer tools, go to the storage or application tab, and look at the cookies listed for a news site. Domains that do not match the site you are visiting are third-party. After blocking, you should see far fewer. Remember to reload the page after changing the setting.

Web Browsers Compared: A Complete Guide for UK Users

Frequently asked questions

Will blocking third-party cookies stop all tracking?

No. It limits one method. Sites can still track you through logins, device fingerprinting and first-party data, so treat it as one layer of protection.

Will I see fewer adverts?

Not necessarily. You will likely see less targeted advertising, but the number of adverts depends on the site.

Can I block cookies on only some sites?

Yes. Both browsers let you set exceptions, so you can be strict by default and relax the rules for specific sites you trust.

Is it safe to block all cookies?

You can, but most websites will stop working properly, since they need first-party cookies for logins and baskets. Blocking only third-party cookies is a better balance.

Conclusion

To block third-party cookies in Chrome, use the Privacy and security page; in Firefox, raise Enhanced Tracking Protection to Strict or Custom. Expect a handful of sites to need exceptions, and add them only for sites you trust. It is a small change that meaningfully reduces how much of your browsing follows you around.