Encrypt Text & Files
Lock a message or file with a password, so only someone who knows it can read it. Strong, standard encryption (AES-256), done on your device: nothing is uploaded.
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How to encrypt and decrypt a message
- On Encrypt, type the message (or choose a file) and a password, twice.
- Click Encrypt, then copy or share the encrypted message (or keep the downloaded file).
- Tell the other person the password a different way: in person, by phone, or in another app.
- They paste the message (or open the file) on Decrypt here, type the password, and read it.
About this tool
Use it to send a password, bank details or anything private over email or chat, or to keep a file safe in cloud storage. Whoever sees the encrypted message without the password sees only random-looking characters.
The encryption is AES-256-GCM, the standard used by banks and messaging apps, and it also proves the message hasn’t been changed: a single altered character and it won’t decrypt. The key is made from your password with PBKDF2-SHA256 and 600,000 rounds and a random salt, which makes guessing passwords hundreds of thousands of times slower. A weak password is still the weak point, so use a long one.
It’s an open format, so you’re never stuck with this site: the message is base64 of “TCRT”, a version byte (1), the rounds (4 bytes, big-endian), a 16-byte salt, a 12-byte IV, then the AES-256-GCM ciphertext and tag, with those first 37 bytes as the additional data. Inside is a byte 1 followed by the text, or a byte 2, the file’s name and type (each with a 2-byte length) and its contents.
Everything happens in your browser with its built-in Web Crypto: nothing you type or choose is sent anywhere, and the page has no ads or trackers.
Questions about encrypting messages
Can you recover my message if I forget the password?
No, and nor can anyone else. That’s the point: there’s no back door. Keep the password somewhere safe, such as a password manager.
How should I send the password?
A different way from the message: if the message goes by email, say the password on the phone or send it in a different app. Anyone who gets both can read it.
Is it really secure?
The encryption itself (AES-256-GCM, with a key made by PBKDF2-SHA256 with 600,000 rounds) is the same standard trusted for banking and government use. How secure your message is depends on the password: four or five random words, or 14+ random characters, can’t realistically be guessed. Check one with our password strength checker.
Is my message or file uploaded?
No. It’s encrypted and decrypted in your browser. You can check: switch on airplane mode and it still works, or watch the live request counter at the bottom of the page.
What can I encrypt?
Any text, or any file up to 300 MB: documents, photos, spreadsheets, archives. Encrypted files end in .tcenc; decrypting gives back the original file with its name.