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Binary, hex and decimal converter

Type a number in any base and see it in binary, octal, decimal and hexadecimal at once.

Private by design: this tool runs in your browser. Nothing you add is uploaded.

How to use it

  1. Type a number in any one box: decimal, binary, hexadecimal or octal.
  2. Watch the other three boxes update as you type.
  3. Copy the form you need.
Screenshot of the Binary converter tool on Sureno, in use
Binary converter in use: a real screenshot of this page.

Questions and answers

How big a number can I convert?

Very large whole numbers, not decimals or negative numbers. Spaces are ignored.

What is binary?

Counting with only 0 and 1, the way computers store numbers. Decimal 5 is 101 in binary.

What is hexadecimal?

Counting in sixteens, using 0–9 and A–F. It is a short way to write binary, as in colour codes like #FF0000.

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