Day Letter privacy policy
Beta version. Last updated 27 October 2026.
The short version. Day Letter is an end-to-end encrypted messenger. Your messages, photos, videos, voice notes, calls, group names and profile details are encrypted on your phone. Our server only passes them on and cannot read them. We never sell data and we show no ads.
Who runs Day Letter
Day Letter is run by Karthik Nugoori. Questions about privacy: privacy@dayletter.app.
What we cannot see
- The text of your messages, and your photos, videos, files and voice notes.
- Your calls (audio and video are encrypted between the phones).
- Group names, group photos and descriptions.
- Your profile photo, About text and any number you add to your profile.
- Your contact list and your backups (backups go to your own phone, iCloud or folder, encrypted).
- Your password. The app sends only a value derived from it.
What our server handles
| What | Why | How long |
|---|---|---|
| Your account id and username | So people can find and message you | Until you delete your account |
| A hash of your login key, and your public encryption keys | Sign-in and starting encrypted chats | Until you delete your account |
| Encrypted messages waiting for an offline phone | Delivery | Until delivered, at most 90 days |
| Encrypted photos, videos and files waiting to be downloaded | Delivery | Until downloaded, at most 3 days |
| Who is in which group, and who you blocked | Delivering group messages; honouring blocks | Until you leave the group or unblock |
| A notification token for your phone | To wake your phone for a new message | Until you sign out |
| Whether you are online right now | Showing your status to your contacts, if you allow it | Kept in memory only, never stored |
| Reports you send about abuse, with any messages you choose to attach | Handling abuse | 90 days |
| Recovery data, if you set up account recovery | Letting you get back into your account | Until you delete your account |
Between people who have accepted each other, Day Letter hides who sent a message from our server ("sealed sender"). Our app server does not log IP addresses or what you do. The call relay's technical log can include the IP addresses of a call's connections; it is deleted after 14 days.
Calls
By default, calls go through our relay server so the other person never sees your IP address ("Protect my IP"). The relay sees the two connections and how long and how much data a call uses. It never sees the call itself.
Companies that help us
- Hetzner (Germany/Finland) hosts our server.
- Cloudflare runs our domain names and stores our encrypted nightly database backups.
- Google (Firebase Cloud Messaging) and Apple (Push Notifications) deliver the wake-up notifications. They see a notification token and when a notification is sent, never the message.
- Apple TestFlight and Google Play deliver the test app. Their own privacy policies apply to them.
Deleting your data
In the app, go to You, then Account, then Delete account. That removes your account and everything linked to it from our server, including messages and files still waiting for delivery. Messages already on other people's phones stay on their phones.
Beta
This is a test version for invited people. Things can break, and we may have to reset test data. We will tell you before we do.
Children
Day Letter is not meant for children under 16.
Changes
If this policy changes, we update this page and the date at the top.