About CookieTelemetry

CookieTelemetry tracks consent management platforms (CMPs) — the tools websites use to show a cookie banner and manage tracking consent — and answers one question most comparison sites don't: does the product actually do what it claims before a visitor clicks anything?

What we measure

For each CMP vendor, we load their own site in a headless browser and record every network request that fires before any consent interaction — no banner is clicked, nothing is simulated. We classify what we observe using Google's own Consent Mode v2 signal (the gcs parameter): a denied ("G100") cookieless ping is recorded separately from a measurement-endpoint request with no consent signal present at all. This is a technical observation, not a compliance determination — see the methodology note on every vendor page for what a given result does and doesn't establish. We also check what cookies and localStorage keys get written before consent. Every result carries the date it was measured. The raw evidence (the browser's network capture) is kept on file and is available on request for a specific result; it is not published on the page.

This is deliberately different from a star rating or a written review: it's a dated, first-hand observation, not a subjective judgment. Each result reflects a single test run (or runs, where noted) — not an ongoing audit — and absence of an observed request does not by itself establish that a tracker was blocked.

What we don't do

We don't publish a subjective rating or "best overall" verdict. We don't accept payment for placement — a vendor's position on this site is never for sale, and being tested does not require or imply any commercial relationship.

Scope, as of today

40 CMP vendors in the directory, 25 of them with a dated single-run measurement of the vendor's own website; for the rest our run produced no result or has not happened yet, and each vendor's page says which. Our lab study, under the published methodology, is in preparation.

How we're funded

Vendors do not fund, review or approve our findings. Until 24 September 2026 we were enrolled in five CMP vendor affiliate programmes; we earned $0 and exited all five on that date. One programme's contractual notice period (CookieYes) runs until 24 October 2026, with no affiliate links and no payments. See our independence statement for the full disclosure and dates. We are building monitoring services for website operators; we do not sell to CMP vendors. A vendor's pricing, certification status, and pre-consent tracking results never depended on, and do not depend on, any commercial relationship.