Privacy

Last updated: August 2026

The short version

Your health data stays on your device — we never see it. We do not sell data, and we do not use it for advertising. This website collects an email address only if you type one in.

Who we are

biokei is made by Biokei Labs. For anything in this policy, write to [email protected] — that address reaches the people who build the product, not a ticket queue.

This website

The waitlist

If you join the waitlist, your email address is stored by Kit, our email provider, on the basis of your consent. You confirm the subscription by email (double opt-in); nothing is stored as a subscription until you do. We use it to tell you when the beta opens and to send occasional product updates — nothing else. Every message has a one-click unsubscribe link, and unsubscribing deletes you from our active list.

Kit is based in the United States, so your email address is processed there. Kit participates in the EU–US Data Privacy Framework and provides the standard contractual safeguards for transfers from the EU.

Analytics and hosting

We use Cloudflare Web Analytics to count page views. It sets no cookies, stores no identifiers, and does not fingerprint or track you across sites — which is why this site has no cookie banner: there is nothing to consent to.

The site is served by Cloudflare Pages. Like any web server, Cloudflare processes your IP address to deliver the page and to protect the site from abuse; we rely on our legitimate interest in running a working, secure website for this. We do not receive or keep those logs.

The app

biokei reads data from Apple Health — such as sleep, heart rate and time in daylight — with your explicit permission, which you can revoke at any time in the Health app. It uses your location to calculate the position of the sun and to fetch the local UV index. Everything — Health data, sun and fasting sessions, grounding logs — is stored on your device and goes no further: the app has no account system and no server of ours behind it.

As Apple requires, and as we would do anyway: data from Apple Health is never sold, never shared with third parties, and never used for advertising or marketing.

Vitamin D and UV dose figures shown in the app are estimates from a model, not measurements, and biokei is not a medical device. It does not diagnose, treat or prevent any condition.

How long we keep things

Your waitlist email stays on the list until you unsubscribe or ask us to remove you. Data in the app stays on your device and is deleted when you delete the app.

Your rights

If you are in the EU, EEA or UK, you have the right to access what we hold about you, correct it, delete it, restrict or object to its processing, take it with you, and withdraw consent at any time. In practice, for us "what we hold about you" is at most one email address — write to [email protected] and we will sort it out. You also have the right to complain to your data protection authority.

Changes

If this policy changes in a way that matters — new data, new recipients — we will say so here and, if you are on the waitlist, tell you by email. The date at the top always reflects the current version.

Contact

Biokei Labs — [email protected]