Cipher Decoder – Brute Force Tool

Don't know which cipher was used? No problem! This tool will attempt to decode your text using Atbash and all 26 Caesar cipher shifts.

Press Enter to decode, Shift+Enter for new line (Max 500 characters: 0/500)

How the Cipher Decoder Works

This brute force decoder attempts to decrypt your text using the most common simple substitution ciphers:

Methods Used:

  • Atbash Cipher – Reverses the alphabet (A↔Z, B↔Y, etc.)
  • Caesar Cipher (Shifts 1-26) – Tests all possible rotation amounts

How to Use:

  1. Paste your encrypted text into the text box
  2. Click "Brute Force Decode"
  3. Review all 27 possible decryptions
  4. Look for readable text – that's likely your answer!
  5. Click the clipboard icon on any result to copy it

Pro Tip

Look for common English words or patterns. The correct decryption will usually be immediately obvious because it forms readable text, while the others will be gibberish.

Example:

If you have the encrypted text: KHOOR ZRUOG

One of the Caesar shifts will reveal: HELLO WORLD (shift of 3)

Tips for Identifying the Correct Result

  • If the message starts with a greeting, look for "HELLO", "HI", or "DEAR"
  • Check for common ending phrases like "SINCERELY" or "REGARDS"
  • ROT13 (Caesar shift 13) is commonly used online
  • Caesar shift 3 was historically used by Julius Caesar

Limitations

This decoder only works with simple substitution ciphers. It cannot decode:

  • Vigenère ciphers (requires a keyword)
  • Modern encryption (AES, RSA, etc.)
  • Transposition ciphers
  • Polyalphabetic ciphers

Related Tools: