Binary ⇄ Text Converter

How text becomes binary

Computers store text as numbers, and this converter shows those numbers in base 2. Your text is first encoded as UTF-8 bytes (the encoding standardised in RFC 3629), and every byte is printed as exactly eight binary digits, with a space between bytes. Plain English letters take one byte each, but other characters take more, so the output grows quickly for accented letters, symbols and emoji.

Worked example: reading "Hi!" by hand

The text Hi! converts to 01001000 01101001 00100001. To check the first byte, add the place values of each 1 bit, reading from the left as 128, 64, 32, 16, 8, 4, 2, 1. The set bits in 01001000 are 64 and 8, giving 72, which is the code for capital H. The second byte is 64 + 32 + 8 + 1 = 105, a lower-case i, and the third is 32 + 1 = 33, an exclamation mark.

Decoding rules

• Input is split on whitespace, and each chunk must be 1 to 8 characters of 0 or 1. A short chunk such as 1000001 is read as its numeric value (65, the letter A), so leading zeros are optional.
• A long unbroken string like 0100100001101001 is rejected with an error, because the chunk is longer than eight digits. Insert a space after every eighth digit and try again.
• The resulting bytes are decoded as UTF-8. If they do not form valid UTF-8, for example a lone 11000011, the affected positions show as the replacement character instead of raising an error.

Common mistakes

• Confusing the number with the text. The byte 00110111 followed by 00110010 is the text "72", whereas the single byte 01001000 is the letter H. To convert an actual number between bases, use the number base converter.
• Expecting one byte per character. Latin-1 and old 7-bit ASCII tables would give é a single byte; UTF-8 uses two, so results can differ from a textbook or another tool.
• Treating binary as secret. It is a different notation for the same data, not encryption. For a related text transformation, see ROT13, and for code-point numbers rather than bits, the text to ASCII converter.