What encryption algorithm is used?

AES-GCM with a 256-bit key, the same authenticated encryption used by TLS and modern disk encryption. GCM mode adds an authentication tag so tampered ciphertext is rejected.

How is the key derived from my passphrase?

PBKDF2 with SHA-256 and 100,000 iterations, using a fresh 16-byte random salt per encryption. That slows brute-force attacks on weak passphrases by orders of magnitude.

What's inside the base64 output?

salt(16 bytes) | iv(12 bytes) | ciphertext + auth tag. The salt and IV are stored alongside the ciphertext so decryption only needs the passphrase.

What happens if I use the wrong passphrase?

AES-GCM authentication fails and the tool reports a clear “wrong passphrase or corrupted input” error. The plaintext is never revealed on a failed attempt.

Is this suitable for storing secrets long-term?

Yes for moderate-sensitivity data. For high-value secrets, use a dedicated password manager or full-disk encryption — those add hardware-backed key storage and stronger KDFs (Argon2, scrypt).

Is my text or passphrase uploaded?

Never. Encryption and decryption happen entirely in your browser via the Web Crypto API. No server is involved.

Encrypt & Decrypt Text

AES-GCM 256 encryption with a passphrase — round-trip in your browser.

100% private — no uploads Security & Crypto ToolsFree & unlimited Read tutorial

See how it works

Watch a quick simulation of this tool in action — no file needed.

How to use Encrypt & Decrypt Text

Follow these steps — everything happens instantly in your browser.

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Step 1. Pick the Encrypt tab and type your secret message.
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Step 2. Enter a strong passphrase — it's the only key to your data.
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Step 3. Click “Encrypt text” to get a base64 ciphertext.
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Step 4. Share the ciphertext; the recipient pastes it in the Decrypt tab with the same passphrase.