https://www.zstd.net/ -> Dead link
http://www.zstd.net/ -> Non HTTPS, 301 Moved Permanently to https://facebook.github.io/zstd
https://facebook.github.io/zstd -> Good link

$ curl -vvvv https://www.zstd.net/
* Host www.zstd.net:443 was resolved.
* IPv6: (none)
* IPv4: 213.186.33.5
*   Trying 213.186.33.5:443...
* connect to 213.186.33.5 port 443 from 172.16.137.57 port 58252 failed: Connection refused
* Failed to connect to www.zstd.net port 443 after 255 ms: Couldn't connect to server
* Closing connection
curl: (7) Failed to connect to www.zstd.net port 443 after 255 ms: Couldn't connect to server


$ curl -vvvv http://www.zstd.net/
* Host www.zstd.net:80 was resolved.
* IPv6: (none)
* IPv4: 213.186.33.5
*   Trying 213.186.33.5:80...
* Connected to www.zstd.net (213.186.33.5) port 80
> GET / HTTP/1.1
> Host: www.zstd.net
> User-Agent: curl/8.7.1
> Accept: */*
>
* Request completely sent off
< HTTP/1.1 301 Moved Permanently
< date: Mon, 19 Jan 2026 06:48:38 GMT
< content-type: text/html
< content-length: 166
< location: https://facebook.github.io/zstd