Encrypt a message entirely in your browser, then attach the ciphertext to a Solana transaction using the Memo program. Only someone with your passphrase can ever read it.
Write & send
Honest read on what this is: the transaction itself, and the fact that an encrypted memo exists, is fully public on Solana forever — this doesn't hide that you sent something. What it hides is the content: the message is encrypted client-side (AES-256-GCM, via your browser's own Web Crypto API) before it ever leaves this page, and your passphrase is never sent anywhere. Share the passphrase with your recipient yourself, through a separate channel — anyone who has it can decrypt the note, and a weak or reused passphrase can be guessed. There's no "forgot passphrase" recovery: if it's lost, that message is unreadable forever.
A generated passphrase is far stronger than one you'd type yourself — use it if you can.
Read & decrypt
Decrypted message
Connect a wallet✕
On mobile, wallets you don't have installed will open their app instead — that's normal, not a bug. Greyed-out wallets aren't installed and have no app to open into.