Number Base Converter — Binary, Octal, Decimal, Hex
Convert a number between binary, octal, decimal and hexadecimal at once. Type a value, pick the base it’s in, and see every other base update live — computed with BigInt so even huge integers stay exact.
How to use it
- 1Enter a number
Type the value you want to convert.
- 2Choose its base
Select whether the input is binary, octal, decimal or hex.
- 3Read the results
Every other base is computed live — copy the one you need.
Bases for programmers
Binary (base 2) mirrors how computers store data; hexadecimal (base 16) is a compact way to write bytes and colours; octal (base 8) shows up in file permissions. Converting between them by hand is error-prone, especially for long values.
This converter uses arbitrary-precision integers, so values beyond the usual 64-bit range convert without rounding — handy for hashes, IDs and bitmasks.
Frequently asked questions
How large a number can it handle?
Any size. Conversion uses BigInt, so large integers convert exactly without floating-point rounding.
Is my input sent anywhere?
No. The conversion runs entirely in your browser; nothing is uploaded.
Can I paste spaces or underscores?
Yes. Spaces and underscores used to group digits (e.g. 1010_1100) are ignored.
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