Convert between hex, decimal, binary, and octal
This number base converter turns a value in one base into every other base at once. Type a number, pick the base you typed it in, and you get the decimal, binary, octal, and hexadecimal versions instantly, ready to copy. It handles the conversions developers reach for most: hex to decimal, decimal to binary, binary to decimal, and everything in between.
What each base is for
- Decimal (base 10) is the everyday number system, digits 0 to 9.
- Binary (base 2) uses only 0 and 1. It is how computers store everything at the lowest level.
- Hexadecimal (base 16) uses 0 to 9 and A to F. It is a compact way to write binary, common in colors, memory addresses, and byte values.
- Octal (base 8) uses 0 to 7. You still see it in Unix file permissions.
The tool uses exact big-integer math, so even very large numbers convert without rounding errors.
Frequently asked questions
How do I convert hex to decimal?
Set the input base to Hexadecimal, type your hex value (for example FF), and read the Decimal result (255). Then copy it.
How do I convert binary to decimal?
Set the input base to Binary, type the binary number (for example 1010), and the Decimal result appears instantly (10).
How do I convert decimal to binary?
Set the input base to Decimal, type your number, and copy the Binary result. The tool also shows the octal and hexadecimal forms at the same time.
Does it work with large numbers?
Yes. The converter uses big-integer arithmetic, so large values convert exactly with no loss of precision.