Glossary · Analytics & web
Do Not Track (DNT)
Do Not Track was an HTTP header and browser setting, standardized as DNT, that signaled a user’s preference not to be tracked across sites — largely abandoned because sites were never legally required to honor it.
DNT sent a simple header (DNT: 1) with every request, expressing intent rather than enforcing anything technically. It required every receiving site to voluntarily change its behavior, and most advertising-funded sites simply ignored the signal — there was no penalty for non-compliance and no way for the browser to verify a site had complied. Major browsers have since removed the DNT setting or stopped sending it by default, and the W3C working group that standardized it disbanded.
DNT’s failure is the reference case for why its successor, Global Privacy Control, was designed differently: GPC is written into law in several US states, giving it an enforcement mechanism DNT never had. The lesson generalizes beyond browser settings — a privacy signal only changes behavior at a service that is either compelled to honor it or architecturally already compliant, not one that merely promises to.
Ciphera products need no opt-out signal for tracking that never happens: Pulse collects no cookies or fingerprints to opt out of, and Relay sends no tracking pixels to suppress.