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Classic Cipher Tool

Encodes and decodes Caesar, ROT13, Atbash, Vigenère and rail-fence ciphers, with a brute-force view.

🔒 Runs entirely in your browserciphercaesarrot13puzzle
Cipher

Shift every letter by a fixed amount. 25 possible keys, all breakable by hand.

Direction

Input

Output

Break a Caesar

Paste an encrypted message and press the button — it will try all 25 shifts and rank them.

Scored against English letter frequencies with a chi-squared test; the best fit is almost always the answer.

None of these protects anything. Caesar has 25 keys, Vigenère fell to Kasiski in 1863, and Atbash has no key at all. They are for puzzles and games — use real encryption for anything that matters.
The substitutions work on the Latin alphabet, so Hangul and anything else non-Latin passes through untouched — which keeps the output readable as a puzzle. Rail fence is the exception: it is a transposition, so it reorders whatever you give it. The Vigenère key advances only on letters, so a space in the message does not consume a key letter.

Feed it from

Morse Code Translator

Converts text to and from Morse and can play it as audible tones at a chosen speed.

Runs entirely in your browser

Random Picker

Picks one or several entries from a pasted list, with weights and an optional spinning wheel.

Runs entirely in your browser

ASCII Text Art

Renders text as large ASCII letters through a real FIGfont renderer, with two bundled fonts and a slot for a .flf of your own.

Runs entirely in your browser

Image to ASCII

Converts a picture into ASCII or ANSI-coloured characters at a chosen width and character set.

Runs entirely in your browser

Next

These accept what this tool produces, so the result can go straight in.

Braille Converter

Converts text into Unicode braille cells per the 2017 Korean braille rules (abbreviations, number and Roman-letter signs, punctuation) or uncontracted English, explaining every cell.

Runs entirely in your browser

Morse Code Translator

Converts text to and from Morse and can play it as audible tones at a chosen speed.

Runs entirely in your browser

Text Encrypt & Decrypt

Encrypts a message with AES-GCM from a passphrase and produces a self-contained Base64 blob.

Runs entirely in your browser

Text to Binary / Hex

Converts text to and from binary, octal, decimal or hexadecimal in a chosen encoding.

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Daily Fortune by Zodiac Animal & Star Sign

Composes one day’s reading for a zodiac animal or star sign from the day’s own 일진 and the traditional temperament of the sign. Seeded from the date, so it is the same all day and refreshing does not reroll it.

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Zodiac Compatibility (궁합)

Two birth dates give two animal signs and two day stems. Reports the exact relation between them — 삼합, 육합, 충, 원진, 형, 파, 해 — and the five-element relation of the day stems, each with the traditional verdict.

Runs entirely in your browser