Number Base Converter
Convert between binary, octal, decimal and hexadecimal, including values too large for a JavaScript number.
Enter something above to see the result.
Converting between bases
Enter a value and pick the base it is written in; every other representation appears at once. Prefixes are understood, so 0xff, 0b1010 and 0o777 can be pasted as-is.
Conversion uses arbitrary-precision integers, so values beyond 2⁵³ — where a JavaScript number silently loses accuracy — convert exactly.
Frequently asked questions
Can I convert very large numbers?
Yes. BigInt arithmetic is used throughout, so a 40-digit hexadecimal value converts without losing a single digit.
What is the 32-bit binary row for?
It zero-pads the value to 32 bits, which is the form you want when reading register values, bit flags or permission masks.
Related tools
Hex EncodeConvert text to hexadecimal (Base16) with a choice of separator, casing and source character set.Color Converter (HEX / RGB / HSL)Convert a colour between HEX, RGB and HSL, with a preview and the WCAG contrast ratio against black and white.Case ConverterConvert between camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, Title Case and more — line by line.Unit ConverterConvert length, mass, data, area, volume, speed, angle and temperature — every unit in the category at once, not just one pair.BMI CalculatorBody mass index with the WHO or the Asia-Pacific thresholds, plus the healthy weight range for your height.Compound Interest CalculatorCompound or simple interest with regular contributions, and a year-by-year schedule.