Binary Code Translator

What binary code is

Binary is a way of writing numbers with only two digits, 0 and 1. Each digit is a bit; a group of eight bits is a byte, which can hold any value from 0 to 255. Computers use binary because their circuits have two stable states, off and on, and everything a computer stores (text, images, sound, programs) is ultimately a very long list of those two states.

Reading a binary number works like reading a decimal one, except each position is worth a power of 2 instead of a power of 10. From right to left the positions are worth 1, 2, 4, 8, 16, 32, 64 and 128. So 01000001 is 64 + 1 = 65.

How text becomes bytes: ASCII and UTF-8

Letters are not numbers, so a character encoding assigns a number to each character. The classic one is ASCII: capital A is 65, B is 66, lowercase a is 97, the space is 32, and the digit 0 is 48. Write each of those numbers as an 8-bit byte and you have the binary form of the text:

• H = 72 = 01001000
• i = 105 = 01101001
• so Hi = 01001000 01101001

ASCII only covers 128 characters: English letters, digits and basic punctuation. Everything else, from é to 日 to emoji, is handled by UTF-8, which keeps the ASCII bytes exactly as they are and uses two, three or four bytes for other characters. That is why this translator, which uses UTF-8, gives é as 11000011 10101001 (two bytes) while every English letter stays one byte.

Going the other way, the decoder splits your input into 8-bit groups, converts each to a number and looks up the character. Groups that are not valid binary are flagged, and if you paste a continuous run of bits without spaces it is chunked into bytes automatically.

Tips for reading binary by eye

• Capital letters start with 010, lowercase with 011, digits with 0011. A byte beginning with 1 is part of a multi-byte UTF-8 character.
• The last five bits of a capital letter give its position in the alphabet: 01000001 ends in 00001 = 1 = A, 01011010 ends in 11010 = 26 = Z.
• Switching case flips one bit: A is 01000001, a is 01100001. Only the 32s bit changes.
• 00100000 (32) is a space. In long strings it is the easiest byte to spot.

Binary vs Morse code: are they the same idea?

People often call Morse code "binary" because it has two symbols, dots and dashes. The comparison is tempting but not quite right. Binary digits are all the same length and are read in fixed groups of eight, so a byte has no need for separators. Morse uses signals of different lengths, and the silences between them are part of the code: a dash is three times a dot, and the gaps between letters and words carry meaning. Morse is better described as a variable-length code with three or four symbols (dot, dash, short gap, long gap), which is also why common letters like E (.) and T (-) are short and rare ones like Q (--.-) are long.

Both, though, are ways of writing text so that a simple physical signal can carry it: a telegraph key for Morse, a voltage for binary. The full comparison, with the same words shown in both systems, is on our Morse code vs binary code page, and you can try the Morse code translator on the same text to see the difference.

Where you will meet binary

Learning to read a few bytes is practical: it helps you understand file sizes (a kilobyte is about a thousand of those bytes), network addresses, color codes in CSS (each of the three channels is one byte), permissions on a Linux system and the error messages that mention "bit 7". It is also a favorite for puzzles, escape rooms and "secret message" activities in class, where a line of 0s and 1s makes a satisfying cipher that any student can decode with a chart.