A mixed content warning appears when an HTTPS page loads a resource (image, script, stylesheet) over plain HTTP. Browsers block the insecure resource or warn about it, since it undermines the page’s overall security.
How to find it
- Open browser DevTools → Console on the affected page; mixed content warnings are logged there with the exact offending URL
- Site-wide scanners can crawl every page for this rather than checking one at a time
How to fix it
- Change hardcoded
http://resource URLs tohttps://(most third-party assets support HTTPS today) - Use protocol-relative or root-relative URLs where the codebase supports it, so this class of bug can’t recur
- For old database content (e.g. CMS posts with hardcoded HTTP image URLs), run a one-time find-and-replace migration
FAQ
Does mixed content actually get blocked, or just warned about?
Scripts and stylesheets are typically blocked outright by modern browsers; images and some other passive content are usually just flagged with a warning, but both should be fixed.