Consent management platform (CMP)

A consent management platform, CMP, is software that presents a person with choices about cookies and data collection, usually through a banner or preference center, records what they chose, and then enforces that choice by controlling which tracking scripts and pixels are allowed to fire. It's the practical mechanism most sites use to comply with consent requirements under laws like General Data Protection Regulation and California Consumer Privacy Act.

A CMP differs from a specific vendor implementation like Google's consent mode, which is a signaling protocol that tells specific ad and analytics tags how to behave, or degrade to modeled data, based on the consent state a CMP has already captured; the CMP is the system of record for consent, and consent mode is one of the ways that state gets communicated downstream. Consent choices typically govern whether cookie-based or other identifier-based tracking can run at all.

CMPs matter to analytics teams because consent state directly determines what data is even available to measure: a visitor who declines analytics cookies produces no session data in tools that respect that choice, which is part of why measurement has shifted toward cookieless tracking and modeled estimates to fill gaps, and toward collecting first-party data under a clear, consented relationship. A common pitfall is technically showing a consent banner while still allowing tags to fire before or regardless of the visitor's choice, which defeats the purpose and can itself be a compliance failure.