Main features
Base conversion, done properly.
Four bases at once
Type one number and binary, octal, decimal and hexadecimal appear side by side - click any result to copy it.
Any base from 2 to 36
Choose the source base and set the target base, covering 2 to 36; signs, decimals, spaces and underscore separators are all understood.
Exact rational maths
Conversions use exact rationals rather than floating point, so huge integers and long decimals stay correct - and you can set the number of decimal places.
History and prefixes
The last 20 conversions are kept and can be copied in one go, and 0b, 0o and 0x prefixes can be pasted straight in.