The team at Chrome has announced their plans for handling mixed content last week on their blog.
We’ll highlight the most important details and what the potential impact is.
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In Chrome 81, mixed images will be auto-upgraded to https://, and Chrome will block them by default if they fail to load over https://. Chrome 81 will be released to early release channels in February 2020.
In other words: if your images, css or JavaScript aren’t able to be served by HTTPS, they’ll be blocked by default.
Source: Chrome’s next steps for security: mixed content checking more important than ever – Oh Dear! blog