Use the HTTPS URL when that is how visitors reach your production service. WebCheck validates TLS during an HTTPS request. The initial site setup also creates a separate TLS check for an HTTPS homepage; adding another HTTPS target does not automatically create another TLS check.
What changes between HTTP and HTTPS
An HTTP target makes an HTTP request and does not perform TLS validation. An HTTPS target makes an HTTPS request, so certificate and protocol validation are required for the request to succeed. A separate TLS check reports certificate details and expiry; it is created for the HTTPS homepage during initial setup.
Redirects are part of the result
If HTTP redirects to HTTPS, WebCheck records the redirect chain and evaluates the final response. A redirect to an invalid, restricted or unexpected destination can still make the check fail.
HTTPS is not downgraded
WebCheck does not follow an HTTPS target down to HTTP. This prevents a secure monitoring target from silently becoming an insecure request. Certificate hostname, chain and protocol validation remain enabled.
What this proves
A successful HTTPS check shows that this monitoring request reached the configured public endpoint and passed its response conditions and TLS validation. It does not prove that every page, browser journey or user network is healthy.