A Web beacon is a tiny graphic image that surveys a user's Web activity. A Web beacon is often contained in a 1X1-pixel graphic image found within an email or a website as is designed to track the Internet activity of a targeted user. When a user visits a website or sends an email that contains a Web beacon, that information is recorded for analytical purposes. The Web beacon may also point to a website by way of the HTML code, thus capturing the Web beacon image. The user's IP address is then recorded as well as how long a particular page was viewed and at what time. The browser type is also noted as are any previous cookies.

Email marketers as well as phishers and spammers use Web beacons to analyze who is clicking on what emails and to collect other email tracking details.

Another name for Web beacon is Web bug.