Tracking pixel

Definition

A tracking pixel is historically a 1x1 transparent image embedded in a web page or email. When the browser loads this image, it sends an HTTP request to the collection server, thereby recording the visit. By extension, the term now refers to any lightweight tag used for advertising tracking (Meta Pixel, LinkedIn Insight Tag).

Technical workings

The classic pixel works without JavaScript: the browser makes a GET request to load the image, and the server records the transmitted information (IP address, user agent, timestamp, URL parameters). Modern pixels are richer JavaScript scripts that collect more data and can react to user interactions.

Advertising pixels typically set third-party cookies to identify users across sites. GDPR and the ePrivacy directive require consent before activating these pixels. A properly configured CMP blocks pixels until the visitor has accepted advertising cookie storage.

Evolution toward server-side

With the disappearance of third-party cookies and tracker blocking by browsers, classic pixels are losing effectiveness. Server-side tracking and Enhanced Conversions offer more resilient and privacy-friendly alternatives.

Have an analytics project?

Let's discuss your tracking, measurement and data needs. Free initial consultation, no commitment.

Book a call