How to convert large UTF-8 strings into ASCII?

Question

I need to convert large UTF-8 strings into ASCII. It should be reversible, and ideally a quick/lightweight algorithm.

How can I do this? I need the source

Answer 1

It is impossible to convert an UTF-8 string into ASCII but it is possible to encode Unicode as an ASCII compatible string.

Probably you want to use Punycode - this is already a standard Unicode encoding that encodes all Unicode characters into ASCII. For JavaScript code check this question

Please edit you question title and description in order to prevent others from down-voting it - do not use term conversion, use encoding.