About the Number Base
The number converter turns integers between binary, octal, decimal, hexadecimal and any base from 2 to 36. It uses BigInt for arbitrary precision, so it stays exact even for very large numbers that would overflow ordinary integer math.
It is useful for reading hex memory addresses, decoding bit flags, working with color values or converting between arbitrary radixes during low-level debugging. Everything is computed locally in the browser, giving you accurate results without rounding errors and without sending your values anywhere.
How to use it
- Enter your number in any supported base.
- Select the input base if it is not auto-detected.
- Read the converted values in binary, octal, decimal and hexadecimal.
- Set a custom base from 2 to 36 for other radixes.
Examples
- Decimal 255 becomes binary 11111111, octal 377, hex FF.
- Hex DEADBEEF becomes decimal 3735928559.
- Convert a 40-digit decimal integer to base 36 exactly, with no precision loss thanks to BigInt.
Frequently asked questions
What bases does it support?
Binary, octal, decimal and hexadecimal directly, plus any custom base from 2 to 36 using digits 0-9 and letters a-z.
Can it handle very large numbers?
Yes. It uses BigInt for arbitrary-precision integer math, so even numbers far beyond 64 bits convert exactly without rounding.
Does it convert decimals or fractions?
No. It works with integers only; fractional values and floating-point numbers are not supported.
Is my input sent to a server?
No. All conversions run locally in your browser, so the numbers you enter never leave your device.
What is the difference between this and a programming language's parseInt?
parseInt is limited by floating-point precision for big values, while this tool uses BigInt to stay exact for arbitrarily large integers.
How do I convert hex to decimal?
Enter the hexadecimal value and read the decimal output; for example, FF becomes 255 and DEADBEEF becomes 3735928559.