Krypton Ø (read “Krypton zero”, sometimes written Krypton 0, or just Krypton) is a social app for iPhone and Android. You share posts, photos, chats and calls only with people you actually know, and our server can’t read any of it.
A closed network, on purpose
Most social apps are built to grow your audience. Krypton Ø goes the other way. There’s no open sign-up and no feed of strangers. You come in through someone who’s already a member, and you share with your Fam: the people you’ve connected with directly.
What you can do
- Post text, photos and videos to your Fam, and reply to each other
- Chat one-to-one or in groups
- Call your Fam by voice
- Make a post disappear 24 hours after it appears
- Choose whether your card is seen by your Fam only or by everyone
Private by default, not as a setting
Posts, replies, photos, profiles, chats and calls are end-to-end encrypted on your phone before they leave it. Our server stores and delivers ciphertext it has no key to open. There’s no secret mode you have to remember to turn on.
Krypton Ø also tries not to know who you know. Your Fam list lives on your phone, and our server’s stored records don’t say who brought whom in. Screenshots and screen recordings of the app come out black, on both iPhone and Android.
No phone number, no email
You join with keys made on your phone. We don’t ask for a phone number or an email address, and the app never uploads your contacts. If you lose your phone, a six-digit PIN and 18 words you wrote on paper bring your account back on a new one.
Who it’s for
Families, close friends, old classmates and small teams. People who want somewhere to talk that isn’t a public feed, and isn’t a chat app tied to their phone number.
How to get in
Ask a member you know for an invitation link. If you don’t have one yet, install Krypton Ø, tap “Ask for an invite” and send your request link to a member you know. The steps are in How joining works, and the full picture of what’s protected is in Security design.