Using the converter
Type on the left. Eight digits appear on the right for every byte, and Separator decides whether the bytes are spaced apart or run together as one string.
Paste binary in and swap the boxes to read it back. If you want the decode direction as the starting point, the binary translator opens that way round and covers the same ground from the other end.
One character is not one byte
The sample above is deliberate. Hi is two characters and two bytes, so it costs 16 digits. The é in café is one character and two bytes, so it costs 16 on its own.
That's UTF-8. A character below 128 is stored as a single byte with a leading 0, exactly as ASCII always did. Anything above that is stored as two, three or four bytes, and the leading bits of the first byte announce how many follow. An emoji usually takes four bytes, so 32 binary digits.
Converters that assume one byte per character break here. They either mangle the accent or silently drop it. Anything this tool can't encode is reported under the output rather than quietly discarded.
Every letter in eight digits
Designed on a placemat in New Jersey
UTF-8 was sketched in September 1992 by Ken Thompson and Rob Pike, in a diner in New Jersey, on a placemat. Thompson wrote the encoder and decoder that evening and the pair had Plan 9 converted within days.
The competing proposal at the time would have broken every existing C program, because it allowed zero bytes inside a character and C strings end at the first zero. Thompson's design keeps ASCII bytes exactly as they were and guarantees no byte of a multi-byte sequence can be mistaken for an ASCII one. Old software carried on working untouched.
That property is why UTF-8 won. By 2008 it had passed every other encoding on the web, and it now accounts for over 98% of pages. A format that let people do nothing beat the formats that asked them to rewrite everything.
Related conversions
Text to hex shows the same bytes in a quarter of the space, because one hex digit stands for four binary ones. ASCII gives you the decimal code point rather than the stored bytes, and the two differ as soon as a character leaves the Latin alphabet.
To see the code point behind a character rather than its bytes, use the Unicode converter.
Questions
How do I convert text to binary?
Type it above and read the result. Each byte becomes eight binary digits, and characters outside ASCII take more than one byte.
Why is my emoji so long in binary?
Most emoji are four bytes in UTF-8, so they take 32 binary digits. Some are several code points joined together and take much more.
Is binary the same as ASCII?
No. ASCII is a table assigning numbers to characters. Binary is a way of writing those numbers. A page can be ASCII and be shown in decimal, hex or binary.
What does 01001000 mean?
It's 72 in decimal, which is a capital H. Eight digits is one byte, and for characters in the ASCII range one byte is one character.