Number Base Converter

This tool converts a number between binary, octal, decimal, and hexadecimal. Change any field and the other fields update.

Invalid character detection: Each input field shows an "Invalid digits" badge when you type a character that is not valid for that base. For example, entering 2 in the binary field or G in the hex field triggers the badge.

Digit grouping: Enable the grouping toggle to see digits separated for readability. Binary groups in blocks of 4, decimal in blocks of 3, and hexadecimal in blocks of 2.

Two's complement: Displays the signed two's complement hex representation of the decimal value. Select 8, 16, 32, or 64 bits. Values outside the signed range for the selected width show an out-of-range message. For example, -1 in 8-bit mode shows FF.

Boundary: The tool uses BigInt, so a value larger than 2^53 stays exact. The two's complement panel only supports standard bit widths. It does not calculate IEEE 754 floating-point representations.