How to use it
- Type the text, or the bytes, into Text or bytes.
- Choose the direction and the base in Conversion, for example Text to binary.
- Pick the Separator between bytes. With None, decimal and octal values get three digits, so the result can be read back.
- If Check shows a message in red, the position it gives is where the first problem is.
Text is bytes, not letters
A computer stores text as bytes. This page uses UTF-8, the encoding of the web (RFC 3629), in which an ASCII letter takes one byte and other letters take more. The Turkish letter ç takes two bytes: 11000011 10100111 in binary, or C3 A7 in hexadecimal.
ç → U+00E7 → UTF-8 C3 A7 → binary 11000011 10100111The four bases
- Binary: 8 digits, 0 or 1, for each byte. The letter A is 01000001.
- Hexadecimal: 2 digits, 0 to 9 and a to f, for each byte. The letter A is 41.
- Decimal: a number from 0 to 255 for each byte. The letter A is 65.
- Octal: 3 digits, 0 to 7, for each byte. The letter A is 101.
What reading refuses
- A digit that is not in the base, such as 2 in binary.
- A decimal or octal value above 255, which is not one byte.
- An incomplete byte, such as seven binary digits.
- Bytes that are not valid UTF-8, such as the single byte 11111111.
Worked example: ç
The letter ç has the code point U+00E7, which is 231 in decimal. In UTF-8 it takes two bytes, C3 and A7, which are 195 and 167 in decimal.
The text Hi ç takes five bytes: 48 69 20 C3 A7 in hexadecimal.
| Conversion | Result for ç |
|---|---|
| Text to binary | 11000011 10100111 |
| Text to hexadecimal | c3 a7 |
| Text to decimal | 195 167 |
| Text to octal | 303 247 |
Frequently asked questions
Why does ç take two bytes?
Every letter outside ASCII takes two or more bytes in UTF-8. ç is U+00E7, which needs the two bytes C3 and A7. The letters A to Z take one byte each, so the byte count differs from the character count.
What is the difference between hexadecimal and binary here?
Both write the same bytes. Binary uses 8 digits for each byte and hexadecimal uses 2, so hexadecimal is shorter and is common in memory dumps and network traces.
Why are decimal numbers written with three digits when there is no separator?
Without a separator, 195167 could be read in several ways. So when the separator is None, every decimal and octal byte gets three digits. With a space or a comma, the numbers stay as they are.
Can I convert a file to binary here?
The page works on text. Paste the text of the file. Reading files whose bytes are not text is not supported, because the result would not be readable.
Is my text sent anywhere?
No. The conversion runs in your browser, and nothing is uploaded or stored.
Sources
- RFC 3629: UTF-8, a transformation format of ISO 10646 (IETF)
- The Unicode Standard, Chapter 3: Conformance (UTF-8 encoding)
Figures and text last checked on Tuesday, November 10, 2026.