Binary, Hex & Number Base Converter
Convert numbers between binary, octal, decimal and hexadecimal.
🔒 Runs in your browser. Nothing you enter is uploaded or stored.
How to use it
Type a whole number in any box and the others update. Very large numbers are supported because the tool uses arbitrary-precision integers. Prefixes such as 0x, 0b and 0o are accepted.
FAQ
Why is 255 important in computing?
It is the largest value one byte (8 bits) can hold: 11111111 in binary, FF in hex. That is why colour channels run from 0 to 255.
Related tools
Roman Numeral ConverterConvert numbers to Roman numerals and Roman numerals back to numbers.Colour Picker & ConverterPick a colour and get its HEX, RGB and HSL codes, plus text contrast ratios.Base64 Encode & DecodeEncode text to Base64 or decode Base64 back to text, with full Unicode (UTF-8) support.