Why it exists

Web analytics is "still an unfair and impenetrable business" — the site owner sees everything, the visitor sees nothing, and the data often flows through third parties that made GDPR a compliance maze. Offen's answer is structural rather than legalistic: analytics run on your own server, data collection is strictly opt-in, every event is end-to-end encrypted so not even the operator can browse a single user's history, and each visitor gets an Auditorium view of their own data — with plain-language explanations of every metric and a working opt-out and delete button.

Main features

• Fair by design — opt-in only (no data without explicit consent), first-party cookies only, no third parties, no ads, no profiling.
• Two-sided Auditorium — operators see all sites' metrics; users see their own sessions across those sites; both views come with explanations of terms like "unique users".
• Essential metrics, honestly — unique users/sessions, page views, top pages, referrers, landing/exit pages, UTM parameters, weekly retention, real-time views; filter by URL, location, referrer and campaign.
• End-to-end encryption — events are encrypted in the browser; the server stores ciphertext it cannot read as a whole.
• Multi-site & team support — one installation, many website accounts, shareable within teams.
• Data minimisation — usage data auto-deletes after 6 months.
• Lightweight self-hosting — a single binary or Docker container behind your reverse proxy; a JS snippet for your pages; localized in six languages (EN, FR, DE, PT, ES, VI).
• Live demo on their own site — visit offen.dev and inspect the data they collected about you.

Who it's for

• Website operators who need real traffic numbers but refuse Google Analytics, both on ethics and on GDPR paperwork.
• NGOs, public institutions and open-source projects that want their analytics to demonstrate their values.
• Privacy-minded developers who'll trade dashboards-with-100-charts for a tool they can explain to a visitor in one sentence.

How it compares

• Matomo — the classic GDPR-friendly choice, self-hostable, but its data model is operator-first (visitors never see their data); Offen's two-sided model is the differentiator.
• Plausible / Fathom — hosted or self-hosted, minimal and privacy-friendly, but still one-directional; Plausible is nicer for marketing funnels, Offen is fairer in the literal sense.
• Umami — lightweight self-hosted alternative with a modern UI, same one-way model.
• The Markup's Blacklight — the flip side: use it to audit the trackers on other people's sites; Offen is how you run a site with nothing for Blacklight to find.

Notes

• Opt-in consent means you will see less data than with consent-banner dark patterns — that's the point; expect roughly the visitors who click "yes".
• The consent banner and Auditorium are localized; custom styling is possible via CSS.
• Started in 2019, NLnet-funded, and declared mature in 2024 along with the Offen Protocol and Consent Tool; development is calm rather than fast.
• No cloud tier: self-hosting is the only deployment, which keeps the story simple — your server, your users' data, nobody else's.

Useful links

• Official site: https://www.offen.dev/
• Source code: https://github.com/offen/offen
• Documentation: https://docs.offen.dev/
• Try it as a user (live demo): https://www.offen.dev/ → "Try as user"