A Tracking Pixel is a small file that is placed on a user’s computer (usually via a web browser) after they visit a website or social media network. A tracking pixel is placed there by a brand so they can monitor the user’s activity on their website (or on the Internet) and serve better ads and content in the future.

Tracking pixels are a primary way to perform a retargeting campaign. When an ad network recognizes the presence of a certain tracking pixel it can display advertisements from the website that placed that pixel on the user’s computer.

Both websites and social media networks (such as Facebook) can place tracking pixels, allowing for a more personal experience for the user after visiting a website, blog, or Facebook page.

Best practices for tracking pixels
The use of tracing pixels by digital marketers should abide by privacy laws and policies. They should be set to expire after a certain amount of time, typically a week or month.