Number Base Converter
Convert between decimal, hexadecimal, binary, and octal. Supports big numbers, bit visualization, and grouped formatting.
About Number Base Conversion
Computers use binary (base 2), but humans prefer decimal (base 10). Hexadecimal (base 16) is a compact way to represent binary — each hex digit maps to exactly 4 bits. Octal (base 8) is used in Unix file permissions (e.g. chmod 755).
Converts between all four bases using JavaScript BigInt for arbitrary precision — there's no upper limit on number size. The bit visualization shows each bit individually, grouped by nibbles (4 bits), making it easy to verify binary representations.
The "Fits in" indicator shows the smallest integer type that can hold the value: uint8 (0-255), int16 (-32768 to 32767), uint32 (0 to ~4.3 billion), int64, or bigint.