Number Base Converter
Convert numbers between binary, decimal, hexadecimal, and octal instantly. Free online base converter.
Features
- ✓Convert between binary, octal, decimal, and hexadecimal
- ✓Type in any field and all others update instantly
- ✓Supports negative numbers
- ✓Validates input characters for each base
- ✓Copy any result with one click
- ✓Works offline — no data sent to servers
How to Use
- 1Type a number in any of the four input fields (binary, octal, decimal, or hex)
- 2All other fields update in real-time as you type
- 3Use the Copy button to copy any converted value
- 4Click "Load Sample" to see an example conversion
- 5Click "Clear" to reset all fields
Examples
Input
255
Output
Binary: 11111111 | Octal: 377 | Hex: FF
Input
10101010 (binary)
Output
Decimal: 170 | Octal: 252 | Hex: AA
Input
FF00 (hex)
Output
Decimal: 65280 | Binary: 1111111100000000 | Octal: 177400
What is a Number Base Converter?
A number base converter (also called a radix converter) translates numbers between different numeral systems. The four most commonly used systems in programming and computer science are binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16). Each system represents the same value using different sets of digits.
Binary (base 2) uses only 0 and 1. It is the fundamental language of computers — every piece of data, from text to images to programs, is ultimately stored as binary. Developers work with binary when dealing with bitwise operations, network masks, file permissions, and low-level hardware programming.
Hexadecimal (base 16) uses digits 0–9 and letters A–F. It is a compact way to represent binary data: each hex digit maps to exactly 4 binary digits (bits). This makes hex popular for memory addresses, color codes (#FF6600), MAC addresses, and debugging. A single byte (8 bits) is represented by exactly two hex digits.
Octal (base 8) uses digits 0–7 and was historically important in early computing. Today it is still used for Unix file permissions (chmod 755), some programming language literals (0o755 in JavaScript/Python), and certain embedded systems. Each octal digit represents exactly 3 binary bits.
Decimal (base 10) is the standard human number system using digits 0–9. While computers work in binary internally, most user-facing values are displayed in decimal. This converter helps you quickly move between the human-readable decimal form and the machine-oriented binary, hex, and octal forms that developers encounter daily.