how to support UTF8 (japanese, arabic, spanish, …) URL's in PHP

Question

For a web application, we need to link to some user generated content. A users types in a title for e.g. a product and we generate an SEO friendly url for that product:

Answer 1

You might need to use IDNA encoding on the non-ASCII portion of the URL.

http://en.wikipedia.org/wiki/Internationalized_domain_name