Number Base Converter
Convert numbers between binary, octal, decimal and hexadecimal.
Binary
11111111
Octal
377
Decimal
255
Hexadecimal
ff
How to use Number Base Converter
- 1Enter a number and select its current base.
- 2All four base representations update live.
- 3Copy any of the results.
Why use this tool
- Converts to all four common bases simultaneously.
- Validates input against the selected base's valid digits.
- Handles large numbers using JavaScript's BigInt.
Frequently asked questions
What's the largest number this supports?
This tool uses BigInt internally, so it handles arbitrarily large integers well beyond JavaScript's normal safe integer limit.