Number Base Converter

Convert a number between binary, octal, decimal, and hexadecimal. Enter a value, choose the base it is written in, and see all four bases at once — arbitrary precision, all in your browser, nothing uploaded.

Convert from

Number

Result

Enter a number above to see it in every base.

How to use Number Base Converter

1
Enter your number
Type or paste a number into the field. Spaces and underscores are ignored, so grouped values like 1010_1101 work too.
2
Choose the starting base
Pick whether your number is written in binary, octal, decimal, or hexadecimal.
3
Read every base at once
The value is shown in binary, octal, decimal, and hexadecimal together, so you can compare or copy whichever one you need.

4
Copy the result
Use the copy button next to any base to put that value on your clipboard.

Frequently asked questions

How do I convert hexadecimal to decimal?

Choose Hex as the starting base and type your hexadecimal value, such as ff. The decimal result, 255, appears instantly alongside the binary and octal forms.

Which bases are supported?

Binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16). Every value is shown in all four at once so you never have to convert twice.

Can it handle very large numbers?

Yes. The converter uses arbitrary-precision big integers, so values far beyond the usual 64-bit limit convert exactly without any rounding.

Does it accept negative numbers?

Yes. Add a minus sign in front of the value and the sign is carried through to every base in the result.

Is anything sent to a server?

No. The conversion runs entirely in your browser, so your numbers never leave your device and nothing is stored.

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