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  3. /Number Base Converter

Number Base Converter

Convert between binary, octal, decimal and hexadecimal instantly, including very large numbers.

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WHAT IS NUMBER BASE CONVERTER?

The Number Base Converter converts arbitrary-precision integers between binary, octal, decimal and hexadecimal, using BigInt arithmetic with no JavaScript number precision limits.

Important

  1. Integers only — fractional values and two's-complement representations are not supported.

How to use?

  1. Choose the input base.
  2. Enter a number and instantly see it in the other three bases.

Frequently asked questions

Why do very large numbers convert exactly?

Conversion runs entirely on JavaScript BigInt, never through the regular Number type, so it never loses precision beyond the safe integer range.

Does it support negative numbers or fractions?

Negative numbers are supported. This version (V1) does not support fractional values, two’s complement, or a fixed bit width.

Can I type a prefix like 0x, 0b, or 0o?

Yes, as long as the prefix matches the selected source base — e.g. a hexadecimal input can start with 0x.

Binary

11111111

Octal

377

Decimal

255

Hexadecimal

FF

Conversion is BigInt-backed end to end — it never passes through JavaScript Number, so values beyond the safe integer range still convert exactly. This version does not support fractions, two’s complement, or a fixed bit width.