Google announced that they are going to mark all HTTP sites as “not secure”in Google Chrome.
The change will take effect in July 2018 with the release of Chrome 68:
“Chrome’s new interface will help users understand that all HTTP sites are not secure, and continue to move the web towards a secure HTTPS web by default. HTTPS is easier and cheaper than ever before, and it unlocks both performance improvements and powerful new features that are too sensitive for HTTP.”
If you haven’t moved your website to HTTPS, you should do so now. Use the website audit tool in SEOprofiler to check if your website still links to HTTP pages on your site: