Number System Converter

Convert between Binary, Octal, Decimal and Hexadecimal number systems instantly. See all four representations simultaneously — with support for large numbers via BigInt.

Convert number base

Enter a number, select its base, and see all representations at once.

All representations
Binary (Base 2)
Octal (Base 8)
Decimal (Base 10)
Hexadecimal (Base 16)

About the Number System Converter

Computers work in binary (base 2), but humans prefer decimal (base 10). Programmers frequently use hexadecimal (base 16) as a compact representation of binary data, and octal (base 8) appears in Unix file permissions and some legacy systems. Our converter lets you switch between all four bases instantly.

How it works

Enter a number in any base and the converter parses it using JavaScript's BigInt for arbitrary-precision arithmetic — meaning it handles numbers far beyond the normal 64-bit floating-point limit. The parsed value is then displayed in all four bases simultaneously. Hexadecimal output uses uppercase letters (A–F).

Input formats

You can type a plain number and select the base from the dropdown, or use standard prefixes: 0b for binary, 0o for octal, and 0x for hexadecimal. The converter auto-detects these prefixes. All processing runs entirely in your browser — nothing is sent to a server.

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