HTTP 505 HTTP Version Not Supported indicates the server does not support the HTTP protocol version used in the request. In practice, this is extremely rare since modern servers support HTTP/1.0, HTTP/1.1, and HTTP/2. You might encounter it when: connecting to a legacy server that only supports HTTP/1.0, sending HTTP/2 to a server that only accepts HTTP/1.1, or when malformed requests are interpreted as an unknown HTTP version.
Response includes the status code, standard headers (including Content-Type), and a small diagnostic JSON body describing the request and returned status.
Simulator URL (copy in the app after load — not a normal link):
https://httpstatus.com/api/status/505
Example request:
curl -i "https://httpstatus.com/api/status/505"