Cipher

Encodes or decodes text using a variety of classical ciphers and encoding schemes.

GET /convert/cipher

Parameters

Parameter	Required	Default	Description
alg	Yes	—	Cipher algorithm (see list below)
text	Yes	—	The text to encode or decode
mode	No	encode	encode or decode

Additional algorithm-specific parameters can be appended as extra query parameters (see per-algorithm options below).

Response

{
  "success": true,
  "alg": "caesar",
  "mode": "encode",
  "input": "HELLO",
  "result": "KHOOR"
}

---

Algorithms

caesar — Caesar Cipher

Shifts each letter by a fixed number of positions.

Extra parameter	Default	Description
shift	3	Number of positions to shift

curl "https://api.uwuapps.org/convert/cipher?alg=caesar&text=HELLO&shift=3"

---

rot13 — ROT13

A special case of Caesar cipher with a shift of 13. Encoding and decoding are the same operation.

curl "https://api.uwuapps.org/convert/cipher?alg=rot13&text=HELLO"

---

a1z26 — A1Z26

Encodes letters as numbers (A=1, B=2, ..., Z=26), separated by dashes.

# Encode: "HELLO" → "8-5-12-12-15"
curl "https://api.uwuapps.org/convert/cipher?alg=a1z26&text=HELLO&mode=encode"

# Decode: "8-5-12-12-15" → "HELLO"
curl "https://api.uwuapps.org/convert/cipher?alg=a1z26&text=8-5-12-12-15&mode=decode"

---

vigenere — Vigenère Cipher

A polyalphabetic substitution cipher using a keyword.

Extra parameter	Default	Description
key	KEY	The keyword for encoding/decoding

curl "https://api.uwuapps.org/convert/cipher?alg=vigenere&text=HELLO&key=SECRET"

---

affine — Affine Cipher

Encodes letters using the formula (a*x + b) mod 26. The value of a must be coprime to 26.

Extra parameter	Default	Description
a	5	Multiplicative key (must be coprime to 26)
b	8	Additive key

curl "https://api.uwuapps.org/convert/cipher?alg=affine&text=HELLO&a=5&b=8"

Valid values for a: 1, 3, 5, 7, 9, 11, 15, 17, 19, 21, 23, 25.

---

bacon — Bacon's Cipher

Encodes letters as 5-character sequences of A and B.

# Encode: "HELLO" → "AABBB AABAA ABABB ABABB ABBBA"
curl "https://api.uwuapps.org/convert/cipher?alg=bacon&text=HELLO&mode=encode"

---

railfence — Rail Fence Cipher

A transposition cipher that arranges characters in a zigzag pattern.

Extra parameter	Default	Description
rails	3	Number of rails (2–20)

curl "https://api.uwuapps.org/convert/cipher?alg=railfence&text=HELLO&rails=3"

---

submono — Monoalphabetic Substitution

Each letter is mapped to another using a 26-character substitution alphabet.

Extra parameter	Required	Description
map	Yes	A 26-letter string defining the substitution (e.g. ZYXWVUTSRQPONMLKJIHGFEDCBA for Atbash)

curl "https://api.uwuapps.org/convert/cipher?alg=submono&text=HELLO&map=ZYXWVUTSRQPONMLKJIHGFEDCBA"

---

polybius — Polybius Square

Encodes letters as coordinates in a 5×5 grid.

Extra parameter	Default	Description
keyword	(none)	Optional keyword to rearrange the square
coords	numbers	Output format: numbers (e.g. 11) or letters (e.g. AA)

curl "https://api.uwuapps.org/convert/cipher?alg=polybius&text=HELLO"

---

tap — Tap Code

Encodes letters using a 5×5 grid tapped out in rows and columns (using dots).

curl "https://api.uwuapps.org/convert/cipher?alg=tap&text=HELLO&mode=encode"

---

nato — NATO Phonetic Alphabet

Converts letters and digits to their NATO phonetic equivalents.

# Encode: "SOS" → "Sierra Oscar Sierra"
curl "https://api.uwuapps.org/convert/cipher?alg=nato&text=SOS&mode=encode"

---

adfgx — ADFGX Cipher

A WWI German field cipher combining a Polybius square with columnar transposition.

Extra parameter	Description
keyword	Polybius square keyword
trans	Columnar transposition key

---

adfgvx — ADFGVX Cipher

An extension of ADFGX that also handles digits.

Extra parameter	Description
keyword	Square keyword
trans	Transposition key

---

bifid — Bifid Cipher

Combines a Polybius square with fractional encryption.

Extra parameter	Default	Description
keyword	(none)	Optional keyword to rearrange the square

---

trifid — Trifid Cipher

A 3D extension of the Bifid cipher using a 27-symbol alphabet.

Extra parameter	Default	Description
alphabet	ABCDEFGHIJKLMNOPQRSTUVWXYZ.	A 27-character string

---

nihilist — Nihilist Cipher

Combines a Polybius square with a numeric key.

Extra parameter	Required	Description
keyword	No	Polybius keyword
numkey	Yes	Numeric key (digits only, e.g. 1234)

---

enigma — Enigma Machine

A simulation of the WWII Enigma machine.

Extra parameter	Default	Description
rotors	I-II-III	Rotor selection (e.g. I-II-III, IV-V-I)
rings	01-01-01	Ring settings (e.g. 01-01-01)
pos	A-A-A	Starting rotor positions (e.g. A-A-A)
plug	(none)	Plugboard pairs (letters, e.g. ABCD for A↔B and C↔D)

curl "https://api.uwuapps.org/convert/cipher?alg=enigma&text=HELLO&rotors=I-II-III&pos=A-A-A"

The Enigma machine is symmetric — encoding and decoding use the same settings.