jeden.day – habit tracker
A private habit tracker
A habit record is personal by nature: it can say what you drink, how you sleep, what you are trying to stop. That makes the question of what the app does with it more than a footnote. jeden.day's answer is short: it stores your habits so you can see them, and nothing else is done with them.
What is collected
For an account: your email address, your habits and entries, the passkeys you register (public keys, never anything that could be used elsewhere), the sessions and connected agents you hold, and — if you sign in with a provider — which provider it was, the identifier and email address it supplied, and the connection and last-use dates. As a guest, nothing at all reaches the server — the record lives in your browser.
The site keeps aggregate counters — how many page views a day, from how many distinct visitors, which pages — and nothing per person: no IP addresses, no user agents, no per-visitor rows. Server logs hold IP addresses for 14 days, to keep the service running and to stop abuse, and nothing else stores them. There is no third-party analytics script. The privacy policy states all of this in the legal register.
What is not done with it
Your record is not analysed, profiled, sold or shown to anyone. There are no ads to target, no "insights" derived from what you log, no partner integrations pulling it out. Signing in needs no Google or Apple account: with email or a passkey, your email provider is the only other party in the loop. If you choose a provider sign-in where one is offered, that provider learns you are signing in and nothing about your habits.
It stays yours
The account menu downloads everything as one JSON file: every habit, every entry, the passkeys' metadata, the agents connected at that moment, any sign-in providers you connected, your calendar preferences, your feedback-board activity, and the consent record. The same file restores into an account later, so a backup is something you can actually use. Deleting the account deletes the data with it, sessions and connections included, and needs no support ticket.
Sensitive changes — a new email address, a new passkey, a new agent connection — require a fresh proof that it is you, so a stale session on a shared device cannot quietly take the account over.
Where it runs
On a single server in a German data centre, operated by the person named in the legal notice. Database backups are kept in an EU object store in Paris, and deleted data leaves them within 14 days. Sign-in mail is sent through an EU transactional mail provider. The privacy policy names each provider.
Questions
Is it really free with no ads? How is it paid for?
It is currently free and there are no ads. It is a small app with small costs, carried by its operator. Paid features may be added in the future; the record would remain yours either way.
Is my data encrypted?
In transit, always. At rest it is stored on the server's disk and in its backups; it is not end-to-end encrypted, since the server has to read it to score your streaks. If you want a record no server can read, guest mode keeps it in your browser only.
Can I use it without giving an email address?
Yes, as a guest, indefinitely. An address is needed only to sync between devices or to download a copy.
What about an AI agent I connect?
It sees exactly the account you approved it for, with full access to that account's habits, until you revoke it. Nothing is connected unless you approve it, and the export lists what was connected when you took it.
Try it now
The grid works in your browser without an account. Sign in later if you want it on a second device.
Open jeden.day