XOR Cipher Encrypt, Decrypt & Bruteforce
Bitwise XOR with a repeating key, plus single-byte bruteforce.
About this tool
XOR is the atom of symmetric cryptography: applied once with a truly random key of equal length it is a one-time pad, but with a short repeating key it becomes a classic puzzle. This tool XORs text or hex input against a key given as text or hex.
The bruteforce tab tries all 256 single-byte keys against your ciphertext and ranks candidates by English letter frequency — the standard first move on many CTF challenges.
Like everything on encrypt.tools, this runs entirely in your browser — nothing you enter is transmitted or stored.
Frequently asked questions about XOR Cipher
What is single-byte XOR bruteforce?+
When a message is XORed with a one-byte key, there are only 256 possibilities. The bruteforce tab tries all of them and ranks results by how English-like they look — a standard first move in CTF challenges.
Why is encryption the same as decryption?+
XOR is its own inverse: applying the same key twice returns the original data. So the same operation both encrypts and decrypts.
Can I use hex keys and data?+
Yes — switch the input and key formats between text and hexadecimal in any combination.
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