A followup blog also worth checking: https://utcc.utoronto.ca/~cks/space/blog/web/URLPresenceNotGoodSignal https://utcc.utoronto.ca/~cks/space/blog/web/URLPres

A followup blog also worth checking: https://utcc.utoronto.ca/~cks/space/blog/web/URLPresenceNotGoodSignal https://utcc.utoronto.ca/~cks/space/blog/web/URLPresenceNotG... > URLPresenceNotGoodSignal > There are a variety of situations where you (in the sense of programs and systems) want to know if a web server supports something or is under someone's control. One traditional way is to require the publication of specific URLs on the web server, often URLs with partially random names. The simplest way to implement this is to simply require the URL to exist and be accessible, which is to say that fetching it returns a HTTP 200 response. However, in light of web server implementations which will return HTTP 200 responses for any URL, or at least many of them, this simple check is clearly not sufficient in practice. The mere 'presence' of a URL on a web server proves very little. > If you need to implement this sort of protocol, you need to require the URL to contain some specific contents.