Number Base Converter

Convert signed arbitrary-precision integers across binary, octal, decimal, and hex, with fixed-width two’s complement

Input base

Integer (sign, prefix, and underscores supported)

Group digitsUp to 10,000 characters; BigInt avoids precision loss

Base 211111111_11111111_11111111_11111111_11111111_11111111_11111111_11111111

Base 81_777_777_777_777_777_777_777

Base 1018_446_744_073_709_551_615

Base 16FFFF_FFFF_FFFF_FFFF

Signed bit width

Two’s complement

Value does not fit this signed width

About Number Base Converter

Convert signed arbitrary-precision integers across binary, octal, decimal, and hex, with fixed-width two’s complement.

No installation is required and input is not permanently stored. Encoding, formatting, image and QR tools run locally in your browser; only network lookups connect to their respective services.