In digital advertising, pixels — also known as marketing pixels, tracking pixels, web beacons, and web bugs — are snippets of code (HTML or JavaScript) or tiny invisible images (measuring 1×1 pixel) that are placed on web pages, usually in the footer, and are used to gather information about website visitors and track their activity.

When a user visits a web page, a pixel loads and sends information to a third-party server. That information enables advertisers to enhance targeting, increase online conversions, measure campaign performance, track conversions, and build audiences based on behaviour. For example, advertisers can show users ads that are more likely to be of interest to them based on their recent online behaviour by inserting ‘retargeting’ pixels on their pages. Or they can track the source of conversions and measure a campaign’s performance by adding a ‘conversion’ pixel on order confirmation pages.

smartclip also fires a DoubleVerify pixel to measure invalid traffic.