ToolBirch

Number Base Converter

Binary, octal, decimal and hexadecimal, exactly.Math & Statistics

Number Base Converter

Convert integers between binary, octal, decimal and hexadecimal. Uses exact BigInt maths.

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

About this tool

Type a value in any base from 2 to 16 and see it in all four common bases at once. Conversion goes through BigInt, so huge integers stay exact, and invalid digits are detected — not silently misread.

How to use the Number Base Converter tool

  1. Type the value. In its current base.
  2. Pick the input base. 2, 8, 10 or 16.
  3. Read all four. Every representation side by side.

Supported formats

Input

  • Plain text or file input

Output

  • Converted or analysed output

Inputs are validated before anything is processed. Invalid values and unsupported files are rejected with a clear error instead of failing silently.

Frequently asked questions

How is validity checked?

The value is re-encoded and compared; a mismatch means invalid digits for that base.

Are negative numbers supported?

No, magnitudes only.

How large can the value be?

As large as BigInt allows — effectively unlimited.

Privacy

Everything you enter stays in this browser tab. There is no upload endpoint for tool inputs, no account, and no server-side copy of your text or files. Results are produced locally and disappear when you close the page.

No account is required and no file is ever uploaded. See the privacy policy for details about analytics and the limited data this site stores.

Known limitations

  • Integers only; fractional bases are not supported.

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