Does not redirect HTTP traffic to HTTPS

All sites should be protected with HTTPS. See the Does not use HTTPS post to learn why and how to set up HTTPS on your server.

How the Lighthouse HTTP redirection audit fails

Lighthouse flags pages that aren't redirected to HTTPS:

Lighthouse audit showing that HTTP traffic isn't redirected to HTTPS

Lighthouse changes the page's URL to HTTP, loads the page, and then waits for the event from the Chrome Remote Debugging Protocol that indicates that the page is secure. If Lighthouse doesn't receive the event within 10 seconds, the audit fails.

How to redirect HTTP traffic to HTTPS

Once you've set up HTTPS, make sure that all unsecure HTTP traffic to your site is redirected to HTTPS: