The importance of the issue
When your website applies the protected HTTPS protocol, all connections are established through a secure protocol. When linking to your site page using HTTP, a browser notifies a user about page insecurity, causing the user to get a negative experience.
If a site has automatic forwarding from HTTP to HTTPS set, it might lead to inner 301 redirections waisting the crawling budget and negatively affecting the site. You should use the highest possible number of “direct” links without redirections within the site.
How to check the issue
Using any browser is enough to check the issue. Open the source code of the flawed page. To do this, click the right mouse button at any spot of the page and choose “browse the code” option, or apply an online tool https://codebeautify.org/source-code-viewer
Find a tag <a href=”http://site.com”>. The presence of the http protocol in a href attribute specifies that there is an issue.
If there is an issue notification, and your site applies a relative URL, find a <base> tag in the website’s code and check its value in the href attribute. The presence of the http protocol in a href attribute specifies that there is an issue. Here is an example:
How to fix this issue
Change the protocol from HTTP to HTTPS in the href attribute of <a> tag. If necessary, change the href attribute value in a <base> tag. Attribute value change within the <base> tag is usually made globally in the website template.
Detect HTTPS pages that links to HTTP
Crawl the website to collect all HTTPS pages with HTTP internal links