Base Converter & Char Codes

See one number in four bases. Big-integer maths means a 20-digit hex ID is never truncated.

Notes

Accepts 0x / 0b / 0o prefixes and underscores (0b1010_1010).
Big-integer maths: values beyond 64 bits are not silently truncated — you get a note instead.
When the input is hex with an even byte count, it is additionally decoded as UTF-8.