Number Base Converter

Convert between binary, octal, decimal, and hexadecimal.

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

Frequently Asked Questions

What is a Number Base Converter?

A number base converter translates a numeric value from one positional numeral system to another. The most common bases in computing are binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16). Binary uses only 0 and 1 and is the native language of digital circuits. Hexadecimal provides a compact representation of binary data, with each hex digit mapping to exactly four binary digits. Our free online converter handles all four bases and updates results in real time as you type. All computation runs in your browser with no data sent to any server.

When to Use a Number Base Converter

  • Converting between hex color codes and RGB binary values in web development
  • Reading memory addresses, register values, or opcodes in debugging and reverse engineering
  • Understanding file permissions in Unix/Linux which use octal notation
  • Working with network addresses, subnet masks, and bitwise operations
  • Learning computer science fundamentals around numeral systems
  • Converting values for embedded systems programming and hardware interfaces

How It Works

Enter a number and select its base from the dropdown. The tool instantly shows the equivalent value in binary, octal, decimal, and hexadecimal. Only valid digits for the selected base are accepted. Copy any result with a single click. All conversions use standard JavaScript number parsing and are performed entirely in your browser.