A pixel is a small invisible code element on a website that is used for this purpose, Record user interactions and send them to external services - mostly for Tracking, Conversion measurement or personalised advertising.
A well-known example is the Facebook Pixel (today usually called Meta Pixel), which transmits data to Facebook/Meta:
- Conversions from Facebook Ads,
- create target groups for remarketing campaigns,
- and user behaviour across different pages.
Technically, a pixel works by loading a 1×1 pixel-sized, invisible graphic that simultaneously contains information such as the page URL, user ID or Event-data is transmitted to the provider.
Since pixels typically client-side are increasingly affected by tracking blockers, consent management and data protection regulations. One alternative is the server-side trackingin which pixel calls are simulated and controlled on the server side.
