Number Base Converter
Convert numbers between binary, octal, decimal and hexadecimal instantly. Type a value, pick the from and to bases, and see the result plus all four bases at a glance — with arbitrary precision for very large integers.
How base conversion works
Enter a number, choose the base it is written in and the base you want, and the result updates as you type. A swap button flips the direction instantly. Invalid digits for the chosen base produce a clear error instead of a wrong answer.
Arbitrary precision
Conversions use BigInt arithmetic, so even very long values convert exactly — no floating-point rounding, no 32-bit overflow. The All bases panel always shows the binary, octal, decimal and hexadecimal forms side by side for quick reference.