Number Base Convert
Convert integers between any base from 2 to 36.
Convert numbers between binary, octal, decimal, and hexadecimal. Free, offline, runs in your browser. Read more Show less
What is number base conversion?
Numbers can be written in any base. Decimal (base 10) is what we use day to day. Binary (base 2) is used by hardware. Octal (base 8) appears in Unix file modes. Hexadecimal (base 16) is used in hashes, colours, and memory addresses.
How to use
Enter a number, pick the source base, and pick the target base. Arbitrary-precision integers are supported through JavaScript BigInt, so long values are exact.
For example, decimal 255 is binary 11111111, octal 377, and hex ff.
FAQ
What characters are allowed?
Digits 0-9, letters A-F (or a-f) for hexadecimal, and for bases above 16 letters up to Z. Underscores and spaces are ignored.
Can I convert fractional numbers?
Only integers are supported. Fractional base conversion requires arbitrary-precision real numbers and is rarely needed.
What about negative numbers?
A leading minus sign is preserved. Two's complement is not applied.