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TOOL · 65 · Data & Utility

Number Base Converter

Convert numbers between binary, octal, decimal and hex — BigInt-powered, works with huge values.

In short
Number Base Converter converts a number between binary (base 2), octal (base 8), decimal (base 10) and hexadecimal (base 16), using JavaScript BigInt so arbitrarily large values are supported.

Processed 100% in your browser — your files never leave your device.

  • Binary (base 2)11111111
  • Octal (base 8)377
  • Decimal (base 10)255
  • Hexadecimal (base 16)FF

How it works

  1. Step · 01

    Choose the base of your input number (binary, octal, decimal, hex).

  2. Step · 02

    Enter the number — arbitrarily large values are supported via BigInt.

  3. Step · 03

    Copy any of the four representations with one click.

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Frequently asked questions

Is there a maximum value?
No practical limit — BigInt handles thousands of digits. Very long inputs may be slow to render.
Does it accept the 0x / 0b / 0o prefixes?
Enter just the digits — the input base you pick already tells the tool how to parse them.
Are my files uploaded to a server?
No. Files are processed directly in your browser using JavaScript and WebAssembly. Nothing is uploaded to our servers, so your documents never leave your device.
Does it work on mobile?
Yes. The tools run in any modern browser on desktop, tablet, or mobile (Chrome, Edge, Safari, Firefox). Very large files may be slower on low-end phones.