Platform
productmetrics.org is two things: the public metrics encyclopedia — definitions, formulas, benchmarks, frameworks, free to cite — and a live metrics platform in invite-only beta. The platform computes cataloged metrics for real websites; the first site on it is this one, which has measured itself with it since July 2026. Three metrics are live so far.
How it works
A small tracker (pm.js, under 3 KB, no cookies) on a site sends session events. The ingest endpoint verifies each request's Origin against the site's domain — set at registration, or pinned automatically from the site's first traffic — drops any batch not marked consent-granted, and rate-limits per site and per sender. Accepted events land in a month-partitioned Postgres store. From there, versioned SQL evaluators run inside the database itself: compute goes to the data, not data to compute. The resulting values render on the metric pages that define them — publicly on this site, and in the dashboard for account holders' own sites.
See it live
Three metric pages currently show this site's own numbers in the “Live from this site” box: average session duration, bounce rate, and daily active users. Each value is computed by the platform from this site's real traffic, and carries a low-sample caption until enough sessions accumulate. The definition and the running implementation share one screen.
The honesty system
A metric renders only when its status is ok. Otherwise it is withheld rather than shown wrong: a wrong number is worse than an absent one.
Privacy is structural, not a policy promise. The store holds page paths only; query strings are stripped server-side. No raw IP is ever stored — a daily-rotating hash counts same-day unique visitors and cannot re-identify anyone across days. Consent is enforced server-side, not just in the tracker. And each evaluator implements the exact formula published on its definition page, so definitions and computations are versioned together.
Where it's going
The planned direction is bring-your-own-database: the same versioned evaluators, deployed inside a customer's own database, so raw events never leave it.
Try it
The beta is invite-only. If you want a site on it, email team@productmetrics.org. The public catalog stays free and needs no account.