When you install the website tracking code on your landing page(s), ClickGUARD is able to track visitors' devices (browsers).

ClickGUARD uses browser local storage to store a Device ID that is used to track visitors across multiple ad clicks, campaigns, keywords, etc. You can later use this information to detect repetitive Ad clicks from the same browser (device).

With ClickGUARD you can create and define a specific "No Device" rule which triggers when ClickGUARD is unable to detect the device from mobile, tablet, and computer, in which case it would be flagged as no device detected, as well as use "device" as a source in almost any other rule type to focus the rule on unique devices.