Number Base Converter

About Number Base Converter

A number base converter changes a number between binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16). Enter a value and pick its base — the converter shows the equivalent in every other base at once, so it does hex to decimal, binary to decimal, decimal to binary, binary to hex, and any other pair. It uses big-integer math, so even very large numbers convert exactly.

Frequently asked questions

How do I convert hex to decimal?

Enter the hexadecimal number, set the input base to Hexadecimal, and read the Decimal row. For example, FF in hex is 255 in decimal. Every other base is shown at the same time.

How do I convert binary to decimal?

Enter the binary number and set the input base to Binary — the Decimal row shows the result instantly. For example, 1010 in binary is 10 in decimal.

How do I convert decimal to binary?

Enter the decimal number with the input base set to Decimal, then read the Binary row. For example, 255 in decimal is 11111111 in binary. The octal and hex equivalents appear at the same time.

Does it handle very large numbers?

Yes. Conversion uses arbitrary-precision integers, so numbers far larger than a normal 64-bit value stay exact — no rounding or lost digits.

What characters are allowed for each base?

Binary uses 0–1, octal 0–7, decimal 0–9, and hexadecimal 0–9 and A–F (case doesn't matter). Anything outside the chosen base's digits is flagged as invalid.