What Is a Mixed Content Warning?
A mixed content warning appears when a page loaded over HTTPS still requests one or more resources over HTTP.
Browsers treat this as a security issue because part of the page is encrypted while other parts are not, which can expose users to interception or tampering.
This warning is common after site migrations to SSL/TLS, CDN changes, theme updates, or plugin installations.
The good news is that most mixed content issues are traceable and fixable once you know which resource types to inspect.
Why Mixed Content Happens
Modern browsers enforce HTTPS to protect page integrity and user privacy.
If your site page loads securely but calls insecure assets, the browser flags the page as partially unsafe.
- Absolute HTTP URLs hardcoded in templates, posts, widgets, or CSS
- Old database entries still pointing to http:// versions of images, scripts, or links
- Third-party assets loaded from providers that do not support HTTPS
- Theme and plugin files generating insecure asset URLs
- CDN or reverse proxy misconfiguration causing protocol mismatches
How to Identify Mixed Content on Your Site
Before you can fix the warning, you need to find the exact files causing it.
Most browsers show a console message or security indicator, but site-wide scanning is faster and more reliable for larger websites.
Check the browser developer console
Open Chrome DevTools, Firefox Developer Tools, or Edge DevTools and look for blocked or upgraded requests.
Mixed content entries often list the file type and source URL, such as an insecure image, script, stylesheet, or font.
Use online HTTPS scanners
Tools like Why No Padlock, JitBit SSL Checker, or site audit features in Semrush and Ahrefs can detect insecure references across pages.
These tools are useful for spotting patterns on templates and shared components.
Review the page source and network requests
Inspect the rendered HTML and the Network tab to identify resources still loaded over HTTP.
Pay close attention to CSS files, JavaScript bundles, image tags, iframe embeds, and font files.
How to Fix Mixed Content Warning on WordPress
If your site runs on WordPress, mixed content is often caused by stored URLs in the database or by theme settings that were never updated after moving to HTTPS.
The safest approach is to update URLs at the source rather than patching each page manually.
Update the WordPress site URL settings
Go to Settings > General and confirm that both the WordPress Address and Site Address use https://.
If either field still uses HTTP, the site may continue generating insecure links.
Run a database search and replace
Use a trusted plugin such as Better Search Replace, or a command-line tool like WP-CLI, to replace http://yourdomain.com with https://yourdomain.com.
This is one of the most effective ways to remove hardcoded legacy links from posts, custom fields, and options tables.
Regenerate theme and page builder assets
Builders like Elementor, Divi, and WPBakery may store asset references in cached CSS or layout data.
Clear plugin caches, regenerate CSS files, and resave templates so the new URLs are written correctly.
Check media library and uploaded files
Images inserted before SSL migration may still point to HTTP in post content or attachment metadata.
Re-uploading the file is sometimes enough, but a database-wide replacement is usually faster for large libraries.
How to Fix Mixed Content Warning Without WordPress
For custom sites, mixed content is usually resolved in templates, server config, or build pipelines.
The goal is to make every asset load with a secure URL or a protocol-relative-safe equivalent.
Replace hardcoded HTTP links in code
Search your templates, JavaScript, CSS, and server-side rendering code for http:// references.
Replace them with https:// or with relative paths where appropriate.
Use environment-based base URLs
In modern frameworks such as Next.js, Nuxt, Laravel, Django, or Rails, the site origin should be set through environment variables or configuration files.
This prevents production assets from pointing to insecure development URLs.
Fix CDN and asset host settings
If assets are served from a CDN like Cloudflare, Fastly, or AWS CloudFront, confirm that the CDN origin and edge URLs use HTTPS.
Also check whether your application is generating HTTP links because it does not recognize the original request as secure behind a proxy.
Do You Need to Update External Resources?
Yes, in many cases.
A page can still trigger warnings if it embeds insecure third-party content, even when your own site is fully HTTPS.
- Video embeds from legacy providers
- Maps, forms, or widgets served only over HTTP
- Analytics scripts included with outdated URLs
- Web fonts hosted on insecure endpoints
If the provider supports HTTPS, update the embed URL.
If not, look for an alternative provider or self-host the asset where licensing allows it.
Can You Use a Content Security Policy?
A Content Security Policy, or CSP, helps control what resources the browser is allowed to load.
It does not fix mixed content by itself, but it can reduce risk and make insecure requests easier to detect.
The upgrade-insecure-requests directive tells supporting browsers to automatically rewrite HTTP requests to HTTPS when possible.
This can reduce warnings, but it should complement, not replace, proper URL cleanup.
How to Prevent Mixed Content From Returning
Once the warning is gone, prevention matters.
New content, plugin updates, and integrations can reintroduce insecure references if your workflow does not enforce HTTPS consistently.
- Use HTTPS-only URLs in templates, menus, and content fields
- Set canonical URLs to the secure version of the site
- Update internal documentation for developers and content editors
- Automate SSL checks in deployment and QA workflows
- Monitor with browser audits and site crawlers after major updates
Which Mixed Content Issues Are Most Common?
The most frequent culprits are images, scripts, and stylesheets because they are often stored in page content or theme files.
Fonts and embedded media are also common, especially on older websites that have undergone partial HTTPS migrations.
Some browsers may auto-upgrade passive content like images, but active content such as scripts is more likely to be blocked.
That means one insecure JavaScript file can break sliders, forms, analytics tags, or entire page features.
How to Verify the Fix
After making changes, reload the page in an incognito window and inspect the console for warnings.
Then run a crawl across key pages and check that all assets resolve with HTTPS and return successful responses.
For extra confidence, test on multiple browsers and devices, because mixed content behavior can vary slightly across user agents and security settings.
What to Remember When You Fix Mixed Content
The best way to fix mixed content warnings is to trace every insecure reference back to its source and update it permanently.
Whether you are working in WordPress, a custom CMS, or a modern framework, the same principle applies: all page resources should load securely over HTTPS.
Once you identify the root cause, the warning is usually straightforward to eliminate and simple to keep from coming back.