What are Mixed Content Warnings?

A browser pop-up message that displays when a user visits a page displaying unencrypted, unsecure content. When a user visits a secure website served over HTTPS, his or her connection with the web server is encrypted with TLS, and is therefore safeguarded from sniffers and man-in-the-middle attacks. If the HTTPS page includes content retrieved through regular, clear-text HTTP, then the connection is only partially encrypted. The unencrypted content is accessible to sniffers and can be modified by man-in-the-middle attackers. Therefore, the connection is no longer safeguarded. When a webpage exhibits this behavior, it is called a mixed content page.