Who redirects Umlaut domain names in browser to transliterated domain name?

Question

I have a domain that contains an Umlaut like that:

https://spaß.de

"ß" may be transliterated to "ss".

Now when I copy and paste this text into Chrome or any other browser, I'm taken to

https://spass.de

However, the 2 domains have different owners, and the owner of "https://spaß.de" will never get any traffic to his site.

Is there any authority that redirects Umlaut domains to transliterated domains, or is the browser responsible for this? I have tried all kinds of browsers, they all show the same behaviour.

Thank you for any insights.

Answer 1

In your case it's the browser. Browsers consider ß ss Ss sS and SS to all have the same semantic meaning when processing web addresses. You can't reliably distinguish between them in a domain name for a web site. If you want to know the details, this process is called Nameprep.

https://en.wikipedia.org/wiki/Nameprep

On the other hand, u and ü are considered to not have the same semantic meaning. A domain name should not have an actual ü in it, but browsers can display, as an example, xn--bcher-kva as bücher. The encoding scheme is called Punycode.

https://en.wikipedia.org/wiki/Punycode