Encrypt or Decrypt Text Instantly
Protect any message with a passphrase using AES-256-GCM encryption — everything runs locally in your browser.
Output format: Base64(salt || IV || ciphertext). Keep it exactly as-is to decrypt later.
About Text Encryption
This tool uses AES-256-GCM, an authenticated symmetric encryption algorithm, to protect text with a passphrase you choose. Encryption and decryption happen entirely in your browser using the Web Crypto API — your text and passphrase are never sent anywhere. Because it's symmetric encryption, the same passphrase is needed to decrypt the message later, so choose one you'll remember or store safely.
Features:
- AES-256-GCM authenticated encryption via the Web Crypto API
- PBKDF2 key derivation with 250,000 iterations and a random salt
- Passphrase strength meter and show/hide toggle
- 100% client-side — nothing is uploaded or stored
How to Encrypt or Decrypt Text
- Choose Encrypt or Decrypt mode
- Enter your text and a strong passphrase
- Click the action button to process it locally
- Copy the result — save your passphrase to decrypt it later
Frequently Asked Questions
Is my text ever uploaded to a server?
No. All encryption and decryption happens locally in your browser using the Web Crypto API. Your text and passphrase never leave your device.
What encryption algorithm does this tool use?
AES-256-GCM, an authenticated symmetric encryption cipher. The key is derived from your passphrase using PBKDF2 with SHA-256 and 250,000 iterations, combined with a random 16-byte salt.
What format is the encrypted output?
The output is a single Base64 string containing the random salt, the random initialization vector (IV), and the ciphertext concatenated together (salt || IV || ciphertext). You need this exact string, unmodified, to decrypt it.
Can you recover my text if I forget the passphrase?
No — and we couldn't even if we wanted to, since we never see your passphrase or text. Without the correct passphrase, the encrypted data cannot be decrypted. There is no recovery option, so store your passphrase somewhere safe.
Why do I need a strong passphrase?
AES-256-GCM itself is extremely secure, but the encryption is only as strong as your passphrase. A short or common passphrase can be guessed even though the algorithm is unbreakable. Use a long, unique passphrase.
What algorithm is used and is it secure?
This tool uses AES-256-GCM, the same authenticated encryption standard used to protect sensitive data across the industry, combined with PBKDF2 for key derivation. It is secure when paired with a strong, unique passphrase — the tool cannot protect against a weak or reused passphrase.
Privacy
All encryption and decryption happens locally in your browser. Your text and passphrase are never uploaded or transmitted anywhere.