HTTP Upgrade-Insecure-Requests Header

The HTTP Upgrade-Insecure-Requests request header sends a signal to the server expressing the client's preference for an encrypted and authenticated response, and that it can successfully handle the upgrade-insecure-requests CSP directive. Upgrade-Insecure-Requests: 1 A client's request signals to the server that it supports the upgrade mechanisms of upgrade-insecure-requests : GET / HTTP/1.1 Host: example.com Upgrade-Insecure-Requests: 1 The server can now redirect to a secure version of the site.