Base Converter
Convert numbers between decimal, hexadecimal, binary, and octal — runs entirely in your browser.
Input base
Decimalbase 10
255Hexadecimalbase 16
0xFFBinarybase 2
11111111Octalbase 8
0o377Convert numbers between decimal, hexadecimal, binary, and octal. Enter in any base, get all four formats instantly. Runs entirely in your browser.
Frequently asked questions
- What are number bases?
- A number base (or radix) defines how many digits a numeral system uses. Decimal uses 10 digits (0–9), binary uses 2 (0–1), octal uses 8 (0–7), and hexadecimal uses 16 (0–9 and A–F).
- Why is hexadecimal common in programming?
- Each hex digit represents exactly 4 bits, so a byte (8 bits) is always two hex digits. This makes hex a compact and readable way to express binary data, memory addresses, and colour codes.
- How do I convert a negative number?
- This tool converts unsigned integers. Negative numbers in binary use two's complement representation, which is outside the scope of this converter.