When an SSL certificate is installed on a website, but the page also calls content from another website without an SSL certificate, the SSL certificate icon will turn grey instead of green:
instead of:
Their site Google Images is also protected with an SSL certificate, but it stays green:
even though they call content (the images that are shown in the results) from websites without an SSL certificate.
How is this possible?
(Screenshots from my own question at Webmasters.SE)
1
If you inspect the images with devtools, you will see that they don’t use external urls, but instead use base64 encoded data uri’s as the image source:
Looking at the source from a results page, the image thumbnails are not being fetched from other sites, but rather being served as base64 encoded data.
Expanding the images does load them from their real address, but that does cause the https icon to turn grey (at least in the most recent version of chrome).