Also known as a web bug, pixel tag or clear GIF, a web beacon is a clear graphic image (typically one pixel in size) that is delivered through a web browser or HTML e-mail. The web beacon operates as a tag that records an end user’s visit to a particular web page or viewing of a particular e-mail. It is also often used in conjunction with a web cookie and provided as part of a third-party tracking service. Web beacons provide an ability to produce specific profiles of user behavior in combination with web server logs. Common usage scenarios for web beacons include online ad impression counting, file download monitoring, and ad campaign performance management. Web beacons also can report to the sender about which e-mails are read by recipients. Privacy considerations for web beacons are similar to those for cookies. Some sort of notice is important because the clear pixel of a web beacon is quite literally invisible to the end user.
Reference(s) in IAPP Certification Textbooks: F138; G66
Associated term(s): Web Bug, Pixel Tag, Tracking Bug, Clear GIF