What are tracking pixels and beacons?
A tracking pixel is usually a tiny invisible image or script that phones home when a page loads, an email opens, or you complete a purchase — reporting your visit to an ad server.
How pixels work on the web
When you load a news article, the page often includes a request to ad.doubleclick.net or facebook.com/tr. The server sets or reads a cookie and logs the event — page view, add-to-cart, purchase.
Conversion APIs and server-side tagging send the same events from the shop's server instead of your browser, which can bypass some ad blockers but still ties events to your identity when you are logged in.
Email pixels and CNAME cloaking
Email open pixels are 1×1 images in marketing mail. When images load, the sender learns you opened the message, roughly when, and sometimes device type.
CNAME cloaking makes a tracker look like a first-party subdomain (e.g. metrics.yourbank.com) so strict cookie rules are harder to apply.
Pixel variants you may encounter
- Image pixels — classic 1×1 GIF/PNG beacons
- JavaScript tags — GTM, Meta Pixel, TikTok Pixel loaders
- Server-side events — purchase webhooks to ad platforms
- Postback URLs — app install attribution to MMPs
Can our tool detect pixels?
We do not load third-party ad tags or report which pixels fired elsewhere. We do show whether cookies are enabled, fingerprint probes succeed, and whether tracker-bait elements were blocked — indirect signs of protection.
- Run a free analysis for browser-level signals.
- Pair with our cookies guide to limit storage pixels rely on.
Check browser tracking signals
Check browser tracking signalsFrequently asked questions
Are pixels the same as cookies?
Related but different. A pixel is often the request that sets or reads a cookie. Blocking cookies hurts pixels; blocking the script stops both.
Do ad blockers stop all pixels?
Many filter lists block known tracker domains. First-party or server-side tagging can still report events without loading the classic third-party script in your browser.
Can I stop email tracking pixels?
Disable automatic image loading in your mail client, or use privacy-focused email that proxies images.