Number Base Converter

Convert between binary, octal, decimal, hex & any base with BigInt.

Convert binary to decimal, hex, octal, or any base 2–36 instantly. Free, no signup, runs in your browser — nothing uploaded. Binary base 2, base 10 to binary…

About Number Base Converter

The Number Base Converter is a free, browser-based tool that instantly converts integers between binary, octal, decimal, hexadecimal, and any custom base from 2 to 36, with simultaneous side-by-side output. Because it uses JavaScript BigInt, it handles arbitrarily large whole numbers with no 32- or 64-bit overflow. It also shows bit length, byte length, sign, a grouped bits view, and optional bitwise operations (AND, OR, XOR, shift left/right). Everything runs locally in your browser — no signup, no uploads, nothing leaves your device.

How to use Number Base Converter

  1. Pick your input base with the From base toggle (Bin, Oct, Dec, or Hex), and set a Custom base (2–36) if you want an extra output row.
  2. Type your value into the Value field. You can include 0x, 0b, or 0o prefixes, underscores, spaces, and a leading minus for negatives.
  3. Read the live results: BIN, OCT, DEC, HEX, and your custom-base row appear at once, alongside bit length, byte length, sign, and a grouped bits view.
  4. Click the copy button next to any output row to copy that representation to your clipboard.
  5. Optionally tick Bitwise operations, choose AND, OR, XOR, << or >>, and enter a second value (parsed in the same input base) to see the result in every base.

Frequently asked questions

Is it free, and do I need an account?
Yes, it is completely free with no signup or account required. Just open the page and start converting.
Is my data uploaded anywhere?
No. All conversion runs entirely in your browser using JavaScript BigInt — nothing you type is sent to a server or leaves your device.
What bases and formats does it support?
It converts between binary (base 2), octal (8), decimal (10), hexadecimal (16), plus any custom base from 2 to 36. Inputs accept 0x, 0b, and 0o prefixes, underscores, spaces, and negative numbers.
How large a number can it handle?
Because it uses BigInt, there is no fixed integer size limit — it converts arbitrarily large whole numbers without 32- or 64-bit overflow. For responsiveness, inputs over about 5,000 characters are not parsed and show a warning instead.
Can it convert decimals or fractions like 3.14?
No. This tool works on whole integers only, so values with a decimal point or fractional part are not supported.
Can it do bitwise math like AND, OR, XOR, and shifts?
Yes. Enable the Bitwise operations option to apply AND, OR, XOR, left shift (<<), or right shift (>>) against a second value, with the result shown in every base. Shift amounts must be whole and non-negative.

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