Number Base Converter

Convert between hex, binary, decimal & octal

Try:

Quick Reference

DecimalHexBinaryOctal
0000000
1100011
88100010
10A101012
15F111117
16101000020
255FF11111111377
256100100000000400

All conversions are performed locally in your browser using JavaScript BigInt. No data is sent to any server. Supports arbitrarily large numbers with full precision.

Number Base Converter

Convert numbers between binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16) instantly. Our converter processes everything locally in your browser with live-as-you-type results — no server calls, no delays, no ads.

Unlike other converters that are limited to 64-bit integers, our tool uses JavaScript BigInt under the hood, allowing you to convert arbitrarily large numbers — hundreds or thousands of digits — with full precision. Whether you're debugging memory addresses, working with network protocols, parsing binary data, or studying computer science, this tool gives you instant, accurate conversions.

Features include automatic digit grouping for readability (4-digit groups for binary and hex, 3-digit groups for decimal), bit-length display, one-click copy, and a clean dark-mode interface designed for developers.

Key Capabilities

  • Four number bases: Binary (base 2), Octal (base 8), Decimal (base 10), and Hexadecimal (base 16) — the four bases every developer needs.
  • Live conversion: Results update in real-time as you type, with no need to click a convert button. Just type and see all four bases instantly.
  • Big number support: Powered by JavaScript BigInt, there's no 64-bit limit. Convert numbers with hundreds of digits without losing precision.
  • Smart input parsing: Automatically strips common prefixes (0x, 0b, 0o), spaces, commas, and underscores from your input so you can paste values from any source.
  • Digit grouping: Toggle automatic digit grouping for readability — binary and hex in groups of 4, octal in groups of 3, decimal with comma separators.
  • Bit length display: See exactly how many bits your number requires — useful for sizing data types and understanding memory layout.

Privacy & Security

All conversions happen entirely in your browser using JavaScript's built-in BigInt arithmetic. No data is sent to any server, no values are logged, and no cookies are used to track your conversions.

This makes it safe to convert sensitive values like memory addresses, cryptographic key fragments, or proprietary data formats. When you close the tab, everything is gone.

How to Use

  1. Select your input base (Binary, Octal, Decimal, or Hexadecimal).
  2. Type or paste your number into the input field. Prefixes like 0x, 0b, 0o are automatically stripped.
  3. All four base conversions appear instantly below as you type.
  4. Click the copy icon next to any result to copy it to your clipboard.
  5. Toggle Group Digits for easier reading of long numbers.
  6. Click any result's base label to swap it into the input field for further conversion.

Frequently Asked Questions