XOR Cipher & Brute-forcer
Applies a repeating-key XOR to text or bytes — the operation at the heart of stream ciphers and countless CTF puzzles — and brute-forces single-byte XOR keys by scoring all 256 candidates against English letter frequencies to reveal the likely plaintext.
Runs 100% in your browser — keys and data never leave your device.
Read the full guide to this tool
Notes
- XOR is its own inverse: encrypting twice with the same key returns the original. That symmetry is why it underlies one-time pads and stream ciphers.
- Repeating-key XOR with a short key is trivially broken by frequency analysis — this is a teaching tool, not real encryption.
- Runs 100% in your browser — keys and data never leave your device.
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