Developer Tools

Number Base Converter (Binary, Hex, Decimal, Octal)

Convert numbers seamlessly between Binary, Octal, Decimal, and Hexadecimal representations with BigInt arbitrary precision.

100% free
Files stay on your device
No sign-up, no watermark

Input Value

Decimal (Base 10)255

Hexadecimal (Base 16)FF

Binary (Base 2)11111111

Octal (Base 8)377

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What is Number Base Converter (Binary, Hex, Decimal, Octal)?

The Number Base Converter translates a number between the four bases programmers use most: decimal (base 10), hexadecimal (base 16), binary (base 2) and octal (base 8). Type a value, choose which base it is written in, and see all four representations at once — for example 255 is FF in hex, 11111111 in binary and 377 in octal. Useful for colour codes, bit masks, file permissions and low-level debugging.

How to use Number Base Converter (Binary, Hex, Decimal, Octal)

1
Enter a number
Type the value you want to convert.
2
Select its base
Choose Dec, Hex, Bin or Oct to tell the tool how to read the input.
3
Copy the result
All four bases are shown together.

Frequently asked questions

Does it handle large numbers?

Yes. Values are converted with arbitrary-precision BigInt arithmetic, so large integers keep every digit.

Can I enter hex with a 0x prefix?

Enter the digits without the prefix and select Hex as the input base.

What is octal used for?

Mostly Unix file permissions, such as 755 or 644.

Last updated: October 13, 2026