This page detects whether or not your browser has a Do Not Track preference set.
"Do Not Track" is a preference that users can set in web browsers to inform websites that they do not want to be tracked, which may help protect them against forms of tracking on the web. Currently, IE10, IE9, IE8, and Firefox support various methods of tracking protection. Today, there is no single definition of what it means to be "tracked," so expressing a preference does not guarantee users that they will be able to block all web sites and content that they may view as being associated with tracking behavior. Users should consider which method of tracking protection is most effective for them.
Below is a table of the current level of browser support for each of these properties. If your browser is sending a DNT preference it will be shown as "DETECTED" in the table.
|Methods to detect a Do Not Track preference||Internet Explorer 9/10||Firefox 11||Chrome||Safari||Internet Explorer 8|
|window.external.InPrivateFilteringEnabled||Supported||Not Supported||Not Supported||Not Supported||Supported|
|window.external.msTrackingProtectionEnabled||Supported||Not Supported||Not Supported||Not Supported||Not Supported|
|navigator.doNotTrack **||Supported||Supported in Firefox 9 or later||Not Supported||Supported in Safari 5.1 on Mac OS 10.7 Lion only||Not Supported|
|DNT : 1 HTTP header **||Supported||Supported||Not Supported||Not Supported||Not Supported|
|** Part of W3C Web Tracking Protection submission. navigator.doNotTrack is implemented with a vendor prefix (navigator.msDoNotTrack) in IE9.|
var tpEnabled = window.external.msTrackingProtectionEnabled();
The DNT HTTP header requires a small bit of server code in order to be accessible from script:
var dntValue = "<%= Request.ServerVariables["HTTP_DNT"] %>";