What Is A Tag?

A tag is a snippet of code, usually JavaScript, placed on a website to collect data and send it to an analytics or marketing platform, such as Google Analytics or the Meta Pixel. Tags can fire independently of one another and, once deployed, often run without ongoing review.

Tags are the basic unit of nearly every analytics and advertising integration on the web. A single page can carry dozens: some deployed through a Tag Management System (TMS), others added years ago and forgotten (see Rogue Pixel). Because tags execute independently, one misconfigured tag doesn’t just fail quietly; it can transmit data nobody intended it to send.