What is the maximum length of an IDNA converted domain name?

Question

First things first:

I\'m storing multiple domains to a database, after I\'ve converted each and every domain name to it\'s IDNA version. What I need to

Answer 1

RFC3492 says this about one of the features os IDNA encoding:

Efficient encoding: The ratio of basic string length to extended string length is small. This is important in the context of domain names because RFC1034 restricts the length of a domain label to 63 characters.

That is it. 63 characters is a maximum length for any domain name regadless of wether it is in IDNA or in ASCII.