Number Base Converter

Convert between binary, decimal, octal and hex

Input Value

From Base

Binary

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Octal

—

Decimal

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Hexadecimal

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About Number Base Converter

Number Base Converter instantly converts a number between binary, octal, decimal, and hexadecimal, showing all four results side by side as you type — entirely in your browser.

How to use Number Base Converter

1Enter your number in the input field.
2Select the base your number is currently in (Binary, Octal, Decimal, or Hexadecimal).
3View the converted value in all four bases at once, updated instantly.
4Click "Copy" next to any result to copy it to your clipboard.

Frequently Asked Questions

What number bases does this converter support?

Binary (base 2), Octal (base 8), Decimal (base 10), and Hexadecimal (base 16) — that's the full set; other custom bases aren't supported.

Is Number Base Converter free to use?

Yes, it's completely free with no registration and no usage limits.

Can I convert negative numbers?

Yes, negative numbers are converted using a standard sign-based representation (not two's complement), so a negative decimal converts to a negative value in the target base.

Do I need to pick a target base to convert to?

No — all four base results are shown side by side simultaneously; there's no separate "convert to" selector.

Tips & Tricks

✓Double-check your "From Base" selection before typing — an incorrect source base will silently produce a wrong (but validly formatted) result.
✓Use the Hexadecimal result directly for CSS/HTML color codes or memory addresses.
✓If a result shows "Invalid," your input contains a digit that isn't valid for the selected source base (e.g., an "8" in binary).
✓Click "Copy" on any of the four result cards to grab that specific base's value.