Web beacon

A web beacon is a technique used on <a href="/facts/Web_page/5JK7xQLe">web pages</a> and <a href="/facts/Email/6pD9GLtI">email</a> to unobtrusively (usually invisibly) allow checking that a user has accessed some content. Web beacons are typically used by third parties to monitor the activity of users at a website for the purpose of <a href="/facts/Web_analytics/F79UAMvw">web analytics</a> or <a href="/facts/Web_analytics/F79UAMvw">page tagging</a>. They can also be used for <a href="/facts/Email_tracking/NvYBCUxr">email tracking</a>. When implemented using JavaScript, they may be called JavaScript tags. Web beacons are unseen <a href="/facts/HTML/sSc3fT78">HTML</a> elements that track a webpage views. Upon the user revisiting the webpage, these beacons are connected to cookies established by the server, facilitating undisclosed user tracking.
Using such beacons, companies and organizations can track the online behavior of web users. At first, the companies doing such tracking were mainly advertisers or <a href="/facts/Web_analytics/F79UAMvw">web analytics</a> companies; later social media sites also started to use such tracking techniques, for instance through the use of <a href="/facts/Button_(computing)/TAJ36ebs">buttons</a> that act as tracking beacons.
In 2017, <a href="/facts/W3C/lGWmhF6M">W3C</a> published a candidate specification for an interface that web developers can use to create web beacons.

Web beacon open-in-new

Web beacon