Search for a tool
Baudot Code

Tool to decode/encode with Baudot. Baudot code is one of the first telecommunication code in binary from a machine (telegraph), it uses 5 bits per character and 2 character sets.


Baudot Code -

Tag(s) : Telecom, Character Encoding

dCode and more

dCode is free and its tools are a valuable help in games, maths, geocaching, puzzles and problems to solve every day!
A suggestion ? a feedback ? a bug ? an idea ? Write to dCode!

Please, check our dCode Discord community for help requests!
NB: for encrypted messages, test our automatic cipher identifier!

Thanks to your feedback and relevant comments, dCode has developed the best 'Baudot Code' tool, so feel free to write! Thank you!

Baudot Code

Baudot Decoder

See also: Morse CodeBinary Code

Baudot Encoder

See also: Morse CodeBinary Code

Answers to Questions (FAQ)

What is the Baudot code? (Definition)

The Baudot code is the name given to the alphabet set up to communicate with the telegraph machine. It has known several variations to adapt to different users and languages. The alphabet was later standardized under the name ITA2 (International Telegraph Alphabet No. 2).

How to encrypt using Baudot cipher

Encryption with the Baudot code uses a substitution/coding alphabet on 5 bits and 2 sets of characters (usually one for letters and the other for numbers and punctuation). The coding alphabet depend on the machine (Baudot type) used:

BaudotOriginal Alphabet (French)
Baudot UKAlphabet modified by the British
ITA2International Telegraph Alphabet No. 2 (most common)
ITA1International Telegraph Alphabet No. 1
MURRAYBaudot Alphabet Modified by Murray (CCITT2)
USTTYITA2 Alphabet Modified for the American Teletypewriter
MTK2ITA2 Alphabet Modified for Russian

The encoding binary alphabet can be used in both directions: MSB (most significant bit) or LSB (least significant bit) first.

Encryption consists in transcribing the characters of the message by their code. To switch between character sets, there are two keys: (switch to letters) and (switch to digits).

Example: Encode the message IA2 BAUDOT with a machine using the international telegraphic alphabet no. 2 (the most widespread).

I00110By default the letter character set is used
11011The next character (2) is a number (therefore absent from the letters' character set), type ⇧ (switch to digits)
(space)00100The space code is the same for each character sets (numbers and letters) in the international alphabet 2
11111The next character (B) is a letter (thus absent from the digits' character set), type ⇩ (switch to letters)

Example: the coded message is then 00110 00011 11011 10011 11111 11001 00011 00111 01001 11000 10000.

How to decrypt Baudot cipher

Decryption with the Baudot code requires knowing the machine and / or the alphabet used. The decoding consists of replacing the 5-bit groups (0 and 1) by their corresponding character in the alphabet.

When the code corresponds to (digits to letters) or (letters to numbers), the character set must be changed.

Example: The encrypted message is 01001 01110 11011 10110 11111 01001 11011 00001


Example: The plain message is DC0D3.

How to recognize a Baudot ciphertext?

The message is a binary code, usually 0 and 1.

The code consists of a number of bits multiple of 5.

What is the Least/Most significant bit first/last?

For 5-bit binary coding, usually the most significant bit is on the left (least on the right)

Example: The value 3 is written 00011 (5bit, least significant bit on the right).

But it is possible to write with the least significant bit to the left

Example: The value 3 is written 11000 (5bit, least significant bit on the left).

What is the International Alphabet n°2?

IA2 is the Baudot variant the most used, here are the codes and their characters:

01000Carriage Return CRCarriage Return CR
00010Line Feed LFLine Feed LF
11011Switch to Digits

What is the WRU code?

On some machines, there was a WRU key (for who are you) which allowed you to request the identification of communicating people.

How to understand the Coldplay album X&Y?

The cover drawing of the album represents colored boxes or blank ones, either in binary 1 or 0, the translation in Baudot code for each line gives X & Y the title of the album.

When was Baudot Code invented?

Émile Baudot described it at the end of the 19th century (about 1877). The electric telegraph had already been invented since 1838.

Source code

dCode retains ownership of the "Baudot Code" source code. Except explicit open source licence (indicated Creative Commons / free), the "Baudot Code" algorithm, the applet or snippet (converter, solver, encryption / decryption, encoding / decoding, ciphering / deciphering, translator), or the "Baudot Code" functions (calculate, convert, solve, decrypt / encrypt, decipher / cipher, decode / encode, translate) written in any informatic language (Python, Java, PHP, C#, Javascript, Matlab, etc.) and all data download, script, or API access for "Baudot Code" are not public, same for offline use on PC, tablet, iPhone or Android !
The copy-paste of the page "Baudot Code" or any of its results, is allowed as long as you cite the online source
Reminder : dCode is free to use.

Need Help ?

Please, check our dCode Discord community for help requests!
NB: for encrypted messages, test our automatic cipher identifier!

Questions / Comments

Thanks to your feedback and relevant comments, dCode has developed the best 'Baudot Code' tool, so feel free to write! Thank you!

Source :
© 2022 dCode — The ultimate 'toolkit' to solve every games / riddles / geocaching / CTF.