Number Base Converter
Enter a value and its base to see it in binary, octal, decimal and hexadecimal at once.
How to use it
- Enter a value Type a number using digits valid for its base (0-9, a-z).
- Choose the base it's written in Pick any base from 2 to 36.
- Read the conversions Binary, octal, decimal and hexadecimal update instantly.
Examples
| 255 (decimal) | ff (hex) |
|---|---|
| 1010 (binary) | 10 (decimal) |
| 777 (octal) | 511 (decimal) |
About this tool
Different number bases are everywhere in computing: binary for raw bits, octal for file permissions, and hexadecimal for colours, memory addresses and byte values.
This converter translates between binary, octal, decimal, hexadecimal and any base up to 36. It uses arbitrary-precision arithmetic, so even very large numbers convert exactly, and it runs entirely in your browser.
Frequently asked questions
What are binary, octal and hexadecimal?
They are number systems with bases 2, 8 and 16. Computers use binary internally, and hexadecimal is a compact way to write binary values.
Can it handle very large numbers?
Yes. Conversions use arbitrary-precision integers, so very long numbers stay exact.
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Updated June 12, 2026