— Encoders & generators

Number Base Converter

Enter a number in binary, octal, decimal or hex and see it in all four bases at once — with big-integer precision.

— What it does

The Number Base Converter is a free tool that converts an integer between binary, octal, decimal and hexadecimal. Choose the base of your input, type the value, and it instantly shows the number in all four bases simultaneously. It validates that your digits are legal for the chosen base and uses BigInt so even very large integers convert without losing precision. Everything runs locally in your browser.

  • Converts between binary, octal, decimal and hex all at once.
  • Validates your input against the selected base and flags illegal digits.
  • Uses BigInt for arbitrarily large integers with no precision loss.
  • Runs entirely in your browser — nothing you enter is uploaded.

How to use it

1

Choose the input base

Select whether your number is binary, octal, decimal or hexadecimal using the segmented control.

2

Type your number

Enter the value. Only digits valid for the chosen base are accepted; anything else shows an error.

3

Read or copy every base

See the value in binary, octal, decimal and hex at once, and copy any representation you need.

Frequently asked

What bases does this converter support?
Binary (base 2), octal (base 8), decimal (base 10) and hexadecimal (base 16). You pick the base of your input and all four outputs update together.
Can it handle very large numbers?
Yes. Conversion uses JavaScript BigInt, so integers far beyond the normal safe-integer limit convert exactly with no rounding or overflow.
Why am I seeing an error on my input?
The input must only contain digits legal for the selected base — for example, binary allows just 0 and 1, and hexadecimal allows 0–9 and A–F. Fractions and spaces are not supported.
Is my data uploaded anywhere?
No. All conversion runs locally in your browser with JavaScript and BigInt. Nothing you type is sent to a server or stored.

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