What Is a Tracking Pixel and How Does It Work in Emails and Websites

A tracking pixel is a tiny image, usually 1 by 1 pixel and invisible, that loads from a company's server. When your email app or browser loads it, the company learns that you opened the email or visited the page, along with details about your device.

How pixels work in email

1. A marketing email includes a hidden image with an address unique to you.
2. When you open the email, your app loads the image.
3. The sender's server records the open: when, how many times, roughly where (from your IP address) and on what device.

That's how newsletters measure "open rates", and how some sales tools tell the sender the moment you read their message.

How pixels work on websites

On websites, "pixel" usually means a tracking script from an ad platform, such as the Meta Pixel, TikTok Pixel or LinkedIn Insight Tag. It reports what you do on the site, such as viewing a product, adding to cart or buying, back to the platform. The platform uses that to measure ads, target you with retargeting ads, and build audiences of people like you.

Many businesses now also send the same data from their servers directly to ad platforms, which browser blocking can't see.

Block email pixels

• Apple Mail: turn on Protect Mail Activity (Settings → Apps → Mail → Privacy Protection on iPhone). It loads images through Apple's servers, hiding your IP address and when you opened the email.
• Gmail: Gmail loads images through Google's servers, which hides your IP address, but the sender can still see that the email was opened. To stop that, go to Settings → See all settings → General → Images → Ask before displaying external images.
• Other apps: look for a setting to block remote or external images.

Block website pixels

• A tracker blocker stops known pixels and tracking scripts from loading.
• Block third-party cookies in Chrome (Settings → Privacy and security → Third-party cookies), which limits how pixels recognize you across sites.
• Reject cookie banners. In the EU and UK, many sites only load ad pixels after you consent. Cookie Auto-Reject clicks reject for you.
• Turn off ad personalization in your Google and Meta account settings.

Make profiles less accurate

Blocking won't catch everything, especially server-side tracking. Ghost Browser visits random sites in the background, adding noise to the interest profiles built from what does get through. For more on where data goes, see how third-party tracking works.