How base converter works
A number base (or radix) is the count of unique digits used to represent values. Base 2 uses 0-1, base 10 uses 0-9, base 16 uses 0-9 and a-f, and so on up to base 36 which uses 0-9 and a-z. Converting between bases means parsing the input in its source base to get the underlying value, then re-formatting that value in the target base.
Enter a value, set the source base it is written in, and the target base you want (any integer from 2 to 36). The converter validates every digit against the source base, parses the integer part exactly using arbitrary-precision integers, and converts the fractional part to up to 16 digits in the target base. It also shows the decimal, binary, octal and hexadecimal forms for reference.
Arbitrary-base conversion is common in programming and cryptography: base 32 and base 36 are used for compact identifiers, base 2 and base 16 for low-level bit work, and unusual bases like base 3 or base 60 occasionally appear in algorithms. This tool covers the full 2-36 range that JavaScript digit characters support.