The Facebook Pixel (now officially called the Meta Pixel) is one of the most widespread tracking scripts on the internet. Estimates suggest it is present on 30–40% of all websites — meaning Facebook receives data about your browsing behaviour on roughly one in three pages you visit, regardless of whether you have a Facebook account.
Here is what it is, how to check if it is running on a site, what it collects and what you can do about it.
What Is the Facebook Pixel?
The Facebook Pixel is a snippet of JavaScript code that website owners embed in their pages. Its primary purposes are:
- Conversion tracking — measuring which Facebook ads led to purchases, sign-ups or other actions
- Retargeting — building audiences of people who visited specific pages, so they can be served ads later
- Lookalike audiences — using your visitor data to find other Facebook users with similar characteristics
When the Pixel fires on a page, it sends data to Facebook including your IP address, browser fingerprint, the page URL, and any custom events the site has configured (such as "viewed product", "added to cart", or "purchased").
How to Check If the Facebook Pixel Is on a Site
The fastest way is our free Tracker & Pixel Scanner. Enter any URL and it will tell you within seconds whether the Facebook Pixel is present, along with every other tracker running on the page.
You can also check manually:
- View source — press Ctrl+U (or Cmd+U on Mac) to view the page source and search for "fbevents.js" or "connect.facebook.net"
- Browser DevTools — open the Network tab and filter for "facebook" to see if any Facebook requests are being made
- Meta Pixel Helper — Facebook's own Chrome extension shows you which pixels are firing on any page
What Data Does the Facebook Pixel Collect?
The standard Pixel collects:
- Your IP address (which Facebook can use to identify you even without cookies)
- Browser user agent (browser type, OS, device)
- The page URL and referrer URL
- A unique browser identifier stored in a cookie
- Custom events defined by the site owner — these can include product prices, search terms, form data and more
In 2022, The Markup found that many health and financial websites were sending sensitive user data — including medical conditions, medication names, and financial details — to Facebook via the Pixel, often without users' knowledge.
Is It Legal?
In the EU, the Facebook Pixel requires explicit user consent under GDPR before it can fire. Many websites load it before consent is given — which is a violation. Several EU data protection authorities have ruled that using the Pixel without proper consent is illegal, and some have issued fines.
In the US, there is no equivalent federal law, but several states (California, Texas, Indiana) have privacy laws that require disclosure of data sharing with third parties like Facebook.
How to Block the Facebook Pixel
uBlock Origin blocks the Facebook Pixel by default. It is the most effective and widely used option — available for Firefox, Chrome, Edge and Safari.
Privacy Badger (from EFF) learns which trackers to block based on cross-site tracking behaviour and blocks the Pixel on most sites.
Firefox with Strict Enhanced Tracking Protection blocks known tracking scripts including the Pixel without any extensions.
Brave browser blocks the Pixel by default on all sites.
If You Own a Website
If you run a site with the Facebook Pixel, you should:
- Ensure the Pixel only fires after the user has given explicit consent if you have EU visitors
- Implement Facebook's Conversions API as an alternative to the browser Pixel for more reliable tracking with less privacy impact
- Check what custom events are configured and whether they inadvertently capture sensitive user data
- Review your privacy policy to ensure it discloses the use of the Pixel and data sharing with Meta
Use our Tracker Scanner to check your own site and see exactly what tracking scripts are present.
