Zellio.io

Text Encryptor

Password-protect text with AES-256 encryption, right in your browser.

Processed locally — nothing is uploaded

About Text Encryptor

The password is the entire security model: the key is derived from it, nothing is stored, and there is no recovery path. A weak password makes AES-256 beside the point, and a forgotten one makes the text permanently unreadable.

Encrypt a message with a password using AES-256-GCM — the same strong, authenticated encryption trusted for sensitive data — then share the result and decrypt it later with the same password. It is the simple way to protect notes, credentials or messages you need to store or send through an insecure channel.

The key is derived from your password using PBKDF2 at 150,000 iterations, which is what makes a short password expensive to attack rather than instant. Without the correct password the ciphertext cannot be read, and there is no reset.

Learn how this works

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Frequently asked questions

How strong is the encryption?

It uses AES-256-GCM with a key derived from your password via PBKDF2 — authenticated encryption that is considered secure for protecting sensitive text. AES-256-GCM is the gold standard in symmetric encryption, used by governments, financial institutions, and security-conscious organizations worldwide. PBKDF2 key derivation applies work factor to your password, making brute-force attacks exponentially harder. The authentication aspect (GCM) verifies that encrypted data hasn't been tampered with, ensuring both confidentiality and integrity. This combination is suitable for protecting personal notes, credentials, and other sensitive information you need to store securely.

What happens if I forget the password?

There is no recovery. The password is the only key, and it is never stored, so an encrypted message cannot be decrypted without it. Keep it safe. This is by design — there are no backdoors, no recovery codes, and no way to decrypt a message if you forget the password. The password never leaves your device, so no company or third party can recover it for you. Use a password manager to store your encryption passwords securely, or commit important passwords to memory if they're critical.

Is my message or password uploaded?

Never. Both the message and password stay in your browser; encryption and decryption happen entirely on your device. All cryptographic operations use browser APIs (WebCrypto) that perform encryption locally without any network communication. Your plaintext messages, passwords, and encrypted results never leave your device, making the tool safe for protecting secrets and confidential information. This privacy-first design means you can confidently encrypt sensitive credentials, personal notes, or business data without any risk of exposure through cloud services or third-party servers.

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Encrypt Text With a Password

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