Number Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal instantly.
Examples
| Input | Result |
|---|---|
| Decimal 255 | Binary: 11111111, Octal: 377, Hex: FF |
| Binary 1010 | Decimal: 10, Octal: 12, Hex: A |
| Hex 1A3F | Decimal: 6719, Binary: 1101000111111, Octal: 15077 |
| Octal 777 | Decimal: 511, Binary: 111111111, Hex: 1FF |
About this tool
Type a number in any of the four supported bases and see instant conversions to the other three. The converter validates your input as you type, so you get immediate feedback if a character is not valid for the selected base. Binary (base 2) uses only 0 and 1, octal (base 8) uses 0-7, decimal (base 10) uses 0-9, and hexadecimal (base 16) uses 0-9 plus A-F.
This tool is handy for developers working with bitwise operations, memory addresses, color values, or file permission masks. Hex is often preferred as a shorthand for binary because each hex digit maps to exactly four binary digits. The converter displays all results simultaneously, so you do not need to run separate conversions for each target base.
Frequently asked questions
What number bases does this converter support?
It converts between binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16). Select your input base and the tool outputs all four at once.
Why do programmers need to convert between number bases?
Different bases show up in different contexts. Binary maps directly to how computers store data. Hexadecimal is a compact way to represent binary values, commonly used for memory addresses and color codes. Octal appears in Unix file permissions.
What happens if I enter an invalid character for the selected base?
The converter validates your input against the selected base and shows an error message. For example, entering "9" in binary mode is flagged because binary only allows 0 and 1.