Private by default
Start tracking without creating an account.
Open Rhythm and log the first event. In free local mode, I do not need your name, email address, or a profile built by ad trackers. Your baby's record stays in that browser unless you turn on household sync.
No ads and no marketing analytics. The landing site counts a fixed set of page and button events without cookies or persistent identifiers.
Local-first has a benefit and a tradeoff
The benefit
The tracker works offline and the free version does not need an account. Your browser stores the baby profiles, events, settings, and history on that device.
The tradeoff
Browser storage is not an indestructible vault. Clearing site data removes the local record, and a browser or device can evict storage even though Rhythm asks it not to.
JSON backup and CSV export are free. If you stay local, export periodically. If losing the record or keeping two devices current would be a serious problem, Plus adds server sync and backup.
Private does not mean isolated
Free local mode keeps the record on one device. Household sync sends a copy to Rhythm's servers so invited caregivers can use the same history. Synced traffic is encrypted in transit and offsite backups are encrypted. Current sync is not end-to-end encrypted, so I technically can access synced records. I do not sell them, use them for ads, or train AI on them. The privacy policy has the full breakdown.
The free app is not a newsletter form
Tracking, custom event types, themes, wake windows, the milk stash, import, JSON backup, and CSV export do not require a paid plan. An email address is required only when you create an account for household sync.
I charge for sync because the servers that keep a household current and backed up cost money to run. It is $5/month or $45/year per household. I do not sell your data, show ads, or send marketing email.
Questions
Do I need an email address?
Not for free local tracking. An account is required for household sync.
What happens if I clear browser data?
The local record can be removed. Export a JSON backup periodically or use Plus if a server backup is important to you.
Can I export everything?
JSON is the full backup format. CSV puts the event history into a spreadsheet-friendly file. Both are available without a subscription.
Your local record stays in the browser unless you choose sync.