Classic Cipher Tool
Encode and decode text with eight classic ciphers — Caesar/ROT13, ROT47, Atbash, Vigenère, Affine, Rail Fence, A1Z26, Bacon — puzzles, not real encryption.
Only the letters A–Z and a–z move, and case is kept (with ROT5 the digits 0–9 move too; a custom alphabet moves only its own characters). Everything else — spaces, punctuation, Hangul — stays where it is.
Your ciphered text appears here…
Chain several methods
Add the method as it is set now; set up the next and add that too, up to 8 steps. The chain runs them in order, or walks them backwards — the last step undone first — to recover a message enciphered through them.
Letter mapping
| Plain | ABCDEFGHIJKLMNOPQRSTUVWXYZ |
|---|---|
| Cipher | DEFGHIJKLMNOPQRSTUVWXYZABC |
Classic ciphers in one tool
Eight ciphers share one box. The dropdown reads Caesar / ROT13 (shift the letters by any
amount, or press ROT13 to set it to 13), ROT47 (shifts printable ASCII, so digits and
punctuation travel too), Atbash (mirror the alphabet, A↔Z), Vigenère
(a repeating keyword), Affine (multiply by a and add b, with a
checked against 26 for you), Rail Fence (write the text in a zig-zag over a number of
rails and read it off in rows), A1Z26 (A=1 … Z=26, letters out as numbers) and
Bacon (each letter becomes a five-symbol A/B group). Pick a method, set its key if it has
one, and toggle between encode and decode. A link can arrive pre-set: add ?method=vigenere to the
address (or affine, railfence, a1z26, bacon, rot47, atbash, caesar) and the page opens on that cipher. The method and its settings — the shift, a and b, the rails, Encode or Decode and the Alphabet — stay in the address as you change them, and Copy link, beside Copy and Download, copies a link that also carries your text, the keyword and a custom alphabet, so whoever opens it sees the whole decryption. Every method at once shows your text through all of them side by side, each with a button to switch to it; Chain several methods stacks steps and runs them forwards to encipher or backwards, last step first, to decipher; and Layout sets the result out in groups or rows with the spaces removed. These are puzzle and teaching ciphers, not secure encryption — everything runs in your browser.
None of these is secure encryption
Every cipher here is broken. Caesar has 25 possible keys, so trying all of them by hand takes a minute. Affine has 311, which is still a short afternoon. Four of the eight take no key at all — ROT47, Atbash, A1Z26 and Bacon — so for those, knowing the method is knowing the message. ROT13 is a Caesar shift of 13, which is its own inverse: applying it twice gives back what you started with, which is why it was used to hide spoilers rather than secrets. Vigenère was the strongest of them for three centuries, and Kasiski published a general break in 1863 by finding the key length in the repeats it leaves behind. This page does those breaks for you: Try every shift ranks every Caesar shift by how much it reads like English, Find the key recovers a Vigenère keyword from the ciphertext alone, and Identify cipher guesses which of this tool's methods a text was written in. If you need something kept, use a tool built for that — the text encrypter on this site uses AES-GCM with a key stretched from your passphrase.
What they are good for
Puzzles, teaching, escape rooms, geocaching, and obscuring text that should not be read by accident — a spoiler, a punchline, an answer key. These ciphers are good at that, because a reader who wants to decode is one click away and a reader who does not is protected from a glance. They are also the clearest introduction to what a key is, why key length matters, and why a cipher that leaks the structure of the plaintext leaks the plaintext. ROT47 is the one to reach for when punctuation matters: it shifts across the printable ASCII range rather than just A–Z, so symbols and digits survive the round trip.
Frequently asked questions
Which ciphers are included?
Eight, all in one dropdown: Caesar / ROT13 (any shift), ROT47, Atbash, Vigenère (a keyword), Affine (multiply and add, with the key checked for you), Rail Fence (a zig-zag over a number of rails), A1Z26 (letters as numbers) and Bacon (five-symbol A/B groups).
Can I use these to protect something?
No. Every cipher here can be broken by hand, most of them in minutes, and four of the eight have no key at all. They hide text from a casual glance and nothing more. For anything that matters, use real encryption.
Why do Encode and Decode give the same ROT13 result?
Because a shift of 13 in a 26-letter alphabet is its own inverse — applying it twice returns the original. So at a shift of 13, Encode and Decode give the same text.
What does ROT47 do differently?
It shifts across the 94 printable ASCII characters rather than the 26 letters, so digits, punctuation and symbols are transformed too instead of passing through unchanged.
Can it break a cipher without the key?
For the ones that have a key, yes. Try every shift lists every Caesar shift undone, the most English-looking first, each with a Use button; Find the key recovers a Vigenère keyword from the ciphertext, and wants a few sentences of English to come out right; Identify cipher undoes each of this tool's methods with its best key and ranks the results. The Letter mapping under the result shows the plain and cipher alphabets (the whole tabula recta for Vigenère), and Caesar's Alphabet setting adds ROT5 on the digits or a custom alphabet of your own.
Can I chain several ciphers, compare them all at once, or group the output?
Yes. Under Chain several methods, set a method and press Add this step to the chain, set up the next and add that too, then choose under Run the chain: Forwards, step 1 first — to encipher, or Backwards, last step first — to decipher a message that went through them; a step that cannot run on the text it is handed is named. Every method at once shows your text through each method with the settings and direction chosen above, marks the ones those settings cannot run, and gives each a Use button. Layout, beside Encode and Decode, sets the result As it comes, In groups, spaces removed, or In rows, spaces removed, with the letters per group or row yours to choose, and Copy and Download take it as laid out.
Can I send someone the whole decryption, not just the method?
Yes. The method and every setting it uses — the Shift, the Affine a and b, the Rails, Encode or Decode, and Caesar’s Alphabet — are kept in the address as you change them, so a reload keeps them. Copy link, beside Copy and Download, copies a link that also carries your text, the Vigenère keyword and a custom alphabet; those three stay out of the address bar and travel only in that link. Older links that name only the method, such as ?method=vigenere or ?method=rail-fence, still open on it.