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Free Text Encryption Tool

Real AES-256-GCM encryption & decryption, 100% in your browser

Text Encryption / Decryption

Important: This tool uses AES-256-GCM encryption with PBKDF2 key derivation. If you lose your passphrase, the encrypted text cannot be recovered — there is no backdoor, no password reset, and no master key.

Real AES-256-GCM

Uses the browser's native crypto.subtle Web Crypto API for authenticated, industry-standard encryption.

PBKDF2 Key Derivation

Your passphrase is stretched into a 256-bit key with a random salt and 100,000 SHA-256 iterations.

Random Salt & IV Every Time

Each encryption uses a fresh random salt and IV, so identical input never produces identical output.

Portable Base64 Output

Salt, IV, and ciphertext are packed into one copyable Base64 string — easy to share or store.

Clear Error Handling

A wrong passphrase or corrupted data fails cleanly with a readable error, never garbled output.

100% Private

All encryption and decryption happens locally in your browser — nothing is ever sent to a server.

The Complete Guide to Browser-Based Text Encryption

This tool lets you encrypt sensitive text — notes, credentials, messages — using real AES-256-GCM encryption, entirely on your own device. There is no server component: your plaintext, passphrase, and ciphertext never leave your browser tab.

Why UtilityX is Different

  • ✅ Real AES-256-GCM Encryption
  • ✅ 100% Free Forever
  • ✅ Zero Server Uploads
  • ✅ PBKDF2 Key Stretching
  • ✅ Unlimited Daily Use
  • ✅ No Account Needed

How the Encryption Works

Your passphrase is never used directly as an encryption key. Instead, it is combined with a random 16-byte salt and run through PBKDF2 with 100,000 iterations of SHA-256 to derive a 256-bit AES key. A random 12-byte IV (initialization vector) is generated for every encryption. The salt, IV, and resulting ciphertext (which includes GCM's built-in authentication tag) are concatenated and Base64-encoded into a single string you can copy, store, or send.

Why You Cannot Recover a Lost Passphrase

This tool has no server, no account system, and no stored copy of your passphrase or plaintext. The decryption key only exists momentarily in your browser's memory, derived fresh from the passphrase you type each time. If you lose the passphrase, there is mathematically no way to reverse AES-256-GCM without it — that is precisely what makes the encryption strong. Always store your passphrase somewhere safe, such as a password manager.

Frequently Asked Questions

What encryption algorithm does this tool use?

AES-256-GCM, an authenticated encryption cipher, via the browser's native Web Crypto API (crypto.subtle). Your passphrase is turned into a 256-bit key using PBKDF2 with a random salt and 100,000 iterations of SHA-256, so the same passphrase never produces the same key twice.

Is my text or passphrase ever sent to a server?

No. All key derivation, encryption, and decryption happen locally in your browser using crypto.subtle. Nothing you type is transmitted, logged, or stored anywhere.

What if I forget or lose my passphrase?

The encrypted text cannot be recovered. This tool has no backdoor, no password reset, and no master key — the passphrase is the only way to derive the decryption key. Losing it means the data is permanently unrecoverable, so store your passphrase somewhere safe.

What happens if I try to decrypt with the wrong passphrase?

AES-GCM includes a built-in authentication tag, so decryption with an incorrect passphrase or corrupted ciphertext fails outright rather than silently returning garbled text. The tool catches this and shows a clear "Incorrect passphrase or corrupted data" message.

Why is the encrypted output different every time, even with the same text and passphrase?

Each encryption generates a fresh random salt and a fresh random IV (initialization vector), which are prepended to the ciphertext and needed for decryption. This randomness means encrypting the same text twice produces different output, which is a deliberate security property that prevents pattern analysis.