Number Base Converter (All Bases)
Free online number base converter — type a number in binary, octal, decimal or hexadecimal and see all bases update live.
Supports arbitrarily large non-negative integers (BigInt under the hood).
About number base (all bases) conversion
Number bases are just different ways of writing the same value: binary (base 2) uses digits 0–1, octal (base 8) uses 0–7, decimal (base 10) uses 0–9 and hexadecimal (base 16) uses 0–9 plus A–F. This converter parses your input as an arbitrary-precision integer and re-renders it in the target base — instantly and privately, in your browser.
Quick reference
1010in binary =12in octal =10in decimal =Ain hexadecimal- Hexadecimal digits:
A=10, B=11, C=12, D=13, E=14, F=15 - Each octal digit maps to exactly 3 binary digits; each hex digit maps to exactly 4
Frequently asked questions
How does the all-bases number converter work?
Type a number into any of the four fields — binary, octal, decimal or hexadecimal — and the other three update instantly. Input is parsed as an arbitrary-precision integer, so very large numbers work too.
What is 255 in binary, octal and hex?
255 in decimal is 11111111 in binary, 377 in octal and FF in hexadecimal.
Is this converter free and private?
Yes — free, no sign-up, and everything runs locally in your browser using BigInt. Nothing is uploaded.