Google chose to gradually roll out the alerts to give website owners time to implement the encryption.
Google today announced the third step in its browser's war on HTTP sites. Two things it could do are 1) create a one-click WordPress plugin to change to https once a certificate is installed and 2) make it so you don't have to create a separate instance in Google Webmaster Central when you switch to https.
On sites that use HTTPS, there is a lock icon with the word "Secure" scribbled next to it.
Google in July introduced HTTP Strict Transport Security (HSTS) on its google.com domain to stop users accidentally navigating to insecure HTTP URLs.
In version 62, the warning was expanded to when users enter any data on an HTTP page, as well as on all HTTP pages in Incognito mode due to an increased expectation of privacy.
Since then, a majority of websites has implemented HTTPS and the remaining is making progress towards that goal, said Chrome security product manager Emily Schechter, said in a blog Jan 8.
As a result, over 78 percent of Chrome traffic on both Chrome OS and Mac are now HTTPS, while 68 percent of Chrome traffic on Android and Windows is also HTTPS.
Chrome now indicates HTTPS-encrypted sites with a green lock icon located next to the address bar. "Progress a year ago was incredible, and it's continued since then", Schechter said.
Some websites have avoided moving to HTTPS because of the cost and difficulty involved with the process, but Google is trying to make the procedure as easy as possible. And now they say time's up as the next rollout of Chrome will mark all those sites that are still on HTTP as "not secure".
If developers need help in shifting to HTTPS, Google has resources like an audit feature in its Lighthouse program. Google is planning to release a new version of its Google Chrome with Chrome 68 and this new update will start rolling out with the updated version.