Toolgeist › Security
Caesar Cipher — Encode/Decode With Any Shift Amount
Shift every letter in your text by a chosen amount — the same substitution cipher Julius Caesar reportedly used for military messages, and the simplest possible introduction to cryptography. With only 26 possible shifts, it can be brute-forced instantly, so treat it as an educational tool, not real encryption.
How to use Caesar Cipher
- Paste your text.
- Choose a shift amount (or brute-force all 25 at once).
- Read the encoded or decoded result.
Frequently asked questions
- How many possible shifts are there?
- Only 25 useful shifts (26 minus the no-op shift of 0), which is why a Caesar cipher can be broken instantly just by trying every shift and reading which one produces real words.
- Was this really used by Julius Caesar?
- According to ancient historical accounts (notably Suetonius), Caesar reportedly used a shift-by-3 cipher for military correspondence — one of the earliest documented uses of substitution ciphers.
- Can I brute-force a Caesar-encoded message here?
- Yes — the brute-force mode shows all 25 possible shifts at once so you can spot the one that produces readable text.
Related Security tools
Also searched for: caesar cipher encoder decoder · caesar cipher brute force · shift cipher online tool
Browse all 738 free tools on Toolgeist →