Oh how does that work then? How does the browser get to the redirect when curl doesn't get any response at all? Is this a DNS thing?

Browsers sometimes try adding things to URLs to try and make them work. Firefox tends to add https:// if http:// fails, perhaps some browsers are adding www.

Funny, if true (doing some research...) I'll add this to the warchest for that classic interview question about what happens when you type a url into your browser.

Definitely was true. Browsersers (at least FF) also used to add .com at the end. I think these days they all just send you to their ad-laden funding source instead if there is no TLD.(*)

https://www.thewindowsclub.com/browser-automatically-adds-ww...

(*) Apparently at least firefox still does the domain fixup instead of search if you type the http:// or https:// prefix so e.g. http://example/ will have you end up on http://www.example.com/

apex domain is different from www cname

I just don't get how the browser gets a response like this (below), and then figures out what to do next. Sister comment said it might just try the common "www." prefix.

        $ dig wixsite.com

        ; <<>> DiG 9.16.1-Ubuntu <<>> wixsite.com
        ;; global options: +cmd
        ;; Got answer:
        ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 65168
        ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

        ;; OPT PSEUDOSECTION:
        ; EDNS: version: 0, flags:; udp: 65494
        ;; QUESTION SECTION:
        ;wixsite.com.   IN A

        ;; Query time: 3 msec
        ;; SERVER: 127.0.0.53#53(127.0.0.53)
        ;; WHEN: Sat Jul 16 09:12:42 AEST 2022
        ;; MSG SIZE  rcvd: 40

        $ nslookup wixsite.com
        Server:  127.0.0.53
        Address: 127.0.0.53#53

        Non-authoritative answer:
        *** Can't find wixsite.com: No answer

Does this mean that the WIX SEO team should really resurrect the record and do a 301, otherwise they are wasting their inbound links?

I think there isn't an inbound link, the crawler is choosing to hit http://wix.com/ if links to wix.com subdomains are common enough. It might be that there are millions of links to www.wix.com and docs.wix.com and user.api.wix.com and not a single (broken) link to wix.com, and they will crawl http://wix.com/ anyway and decide that "the site is dead". This is a problem with their methodology.

Yes this goes to “what is a site?” and “who/what is controlling what sub domains”. Especially with things like GitHub.io, and indeed wix. I think ignoring dead apex domains when a subdomain worked would have been a good extra pass for the methodology.

Perhaps that is the reason for the apex domain to be dead in the first place - to communicate that the subdomains are the real roots of separate sites. Similarly, TLDs themselves are not supposed to have any A records (although there are some that do).

As someone hypothesizes above, it’s common for browsers to add www. to domains that don’t resolve.

I'm not sure if it's because I have my browsers set to generally "do what I say" or because I'm using a filtering proxy, but Firefox doesn't seem to try again if I just put "wixsite.com" in the address bar --- it gets a Host Not Found from the proxy and stops.

That is weird - it does the fixup from http://wixsite/ to http://www.wixsite.com/ but leaves http://wixsite.com/ alone.