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🔢 Number Base Converter

Convert any integer between binary (base 2), octal (base 8), decimal (base 10), hexadecimal (base 16), or any custom base up to 36 — instantly, for free, entirely in your browser with no uploads or logins.

Input
Converted Values

About

This tool converts integers between binary, octal, decimal, hex, and any custom radix from 2 to 36 using BigInt arithmetic, so it handles arbitrarily large numbers without rounding errors. Everything runs locally in your browser — no server, no account, and no data ever leaves your device. Your last input is automatically saved to localStorage so you can pick up exactly where you left off.

How to use

  1. Enter the number you want to convert in the Value field.
  2. Select the base of your input number (Decimal, Binary, Octal, Hexadecimal, or Custom).
  3. If you choose Custom, enter any radix between 2 and 36 in the Custom Base field.
  4. All converted values appear instantly in the results panel — Binary, Octal, Decimal, Hex, and your custom base.
  5. Click the copy button next to any result to copy it to your clipboard.

FAQ

Is this number base converter free to use?
Yes, completely free — no account, subscription, or payment required, now or ever.
Do you upload my numbers to a server?
No. All conversion happens locally in your browser using JavaScript. Your data never leaves your device.
Does it work offline?
Yes. Once the page is loaded, the converter works fully offline with no internet connection needed.
What bases or radixes does it support?
It supports binary (base 2), octal (base 8), decimal (base 10), hexadecimal (base 16), and any custom radix from 2 to 36.
Can it handle very large numbers or negative numbers?
Yes. The converter uses BigInt arithmetic internally, so it handles arbitrarily large integers and negative numbers without floating-point rounding errors.