Encrypted for anyone.
Proven for the people you've met.

Add someone by standing within 100 yards of them — the most secure link two phones can make. Or send an invite, sealed to the industry standard for private chats. Either way, what you say is yours alone.

Coming soon to the App Store

Encryption from beyond the state of the art

Every message, photo, file and voice note is sealed on your phone before it goes anywhere, with keys that generate a fresh lock for every single message — and on recent iPhones, the seal includes ML-KEM-768 post-quantum encryption: math chosen to survive the quantum computers that don't exist yet. Someone recording your traffic today, hoping to crack it in a decade, is collecting garbage.

The handshake no hacker can intercept

Most "secure" messengers have a dirty secret: the keys pass through their servers, and you're trusting them not to swap the locks. StrongChat's answer is physics. Meet in person and your phones hand each other their keys directly, over a local link we have no part in — and each phone checks what it received against what our server said. If those ever disagreed, you'd be told, loudly. Can't meet? The invite link carries your key to them over a channel we don't control — though theirs still comes back through us, which is exactly why the same-room check matters more on that path than on any other. Either way, confirm it's really them with a sound your two phones play to each other, derived from your shared secret — a check no distant impostor can fake.

We can't read your messages. Neither can anyone who robs us.

Our server relays and holds only ciphertext it cannot open, stored without recording which direction a message went. A photo sent to an offline friend waits at most 48 hours, sealed, then vanishes. A hacker with a full copy of our database gets gibberish. A subpoena gets gibberish. That's not a promise about our character — it's a fact about what exists.

Don't trust us. Audit us — from inside the app.

Open Settings and tap "What our server knows." It shows you your own record, live from our database, including the raw stored form of your last message. If we ever stored something readable, you'd be looking at it. It is your account record rather than a database dump — the full inventory is in the privacy policy — but the part that is about you is right there, and no other messenger dares put that screen in your hands.

Built like it matters

• Screenshot alerts. If they screenshot the chat, their app tells you — as long as you are both connected at that moment. It's a courtesy between honest apps rather than a lock. Screen recording only blanks your own content and is not reported to your contact, and nothing can stop someone pointing a second camera at a screen. We won't pretend otherwise.
• Your phone is the vault. Lose it and your messages die with it — nothing readable exists on our server to leak, subpoena, or resell. Your own device backup is the one other place they could be, and that one is yours. We think that's a feature.
• No engagement machinery. No feed to scroll, no streaks, no "seen at 11:42." Software that wants your attention is software that sells it. This is a place to talk, not a place to be farmed.
• Notes to yourself. A private thread with nobody else in it, sealed with your own key and never sent anywhere. Useful on its own, and the one part of the app that works before you have added a single person.
• Confirm they read it. Ask someone to confirm they have read a specific message and get back a note signed with a key only their phone holds. Different from a read receipt: that proves a screen displayed something, this proves a person was asked and answered.
• Messages that need two people to open. Split the key to a message across contacts you choose, so the recipient cannot read it alone. Useful when a single phone being taken should not be enough. The helpers only ever hold a piece of a key and are told plainly that they cannot read a word of it.
• Delete means delete. Wipe your server data from inside the app and watch the "What our server knows" screen empty out — messages, attachments, the lot. Deleting the account takes the account with it. Falsifiable, like everything else here — and our nightly backups roll off after fourteen days, which is when the last copy goes.

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