Mixed Content Errors in Browser: What They Are and How to Fix Them

PostedApril 11, 2025

UpdatedApril 14, 2025

ByServers9

Mixed content errors are a common issue many website owners and developers encounter, especially after migrating a site from HTTP to HTTPS. These errors can affect your website’s security, SEO, and user experience. In this post, we’ll explore what mixed content is, why it’s a problem, how it affects your site, and how to identify and fix it.

✅ What Is Mixed Content?

Mixed content occurs when a webpage is loaded over HTTPS (secure), but it includes resources (like images, scripts, stylesheets, videos, etc.) that are loaded over HTTP (insecure).

📌 Example:

Let’s say your webpage URL is:

https://example.com

But it tries to load an image like:

http://example.com/images/logo.png

That image is being loaded over an insecure protocol (HTTP), even though the page itself is secure (HTTPS). This is what we call mixed content.

🔐 Why Is Mixed Content a Problem?

Mixed content undermines the security of your website. Even though the page itself is served over HTTPS, the insecure elements can be intercepted or manipulated by attackers.

⚠️ Key Risks:

Man-in-the-middle (MITM) attacks on insecure scripts or iframes.
Security warnings shown by modern browsers.
Blocked resources resulting in broken styles, images, or scripts.
Reduced trust from users who see browser warnings.
Negative impact on SEO, as search engines prioritize fully secure websites.

🔍 Types of Mixed Content

There are two main types of mixed content:

1. Passive Mixed Content

Includes elements like images, audio, or videos. These do not directly interact with the page and are less dangerous but still flagged by browsers.

2. Active Mixed Content

Includes scripts, iframes, stylesheets, or AJAX calls. These can interact with or modify the page, making them much riskier. Most browsers block active mixed content completely.

🧭 How to Identify Mixed Content

There are several ways to detect mixed content on your website:

🔧 1. Browser Console

Open your website in Chrome.
Press Ctrl+Shift+I or right-click > Inspect > Console tab.
Look for warnings like: “Mixed Content: The page at ‘https://…’ was loaded over HTTPS, but requested an insecure resource ‘http://…’.”

🔧 2. Online Tools

🔧 3. Website Crawlers

Tools like Screaming Frog SEO Spider or SEMrush can scan your entire site and flag mixed content URLs.

🛠️ How to Fix Mixed Content Errors

Here’s a step-by-step guide to resolving mixed content issues:

✅ 1. Update URLs

Change all http:// resource links to https:// if the resource is available over HTTPS.

✅ 2. Use Relative URLs

Instead of hardcoding full URLs, use relative paths:

<img src="/images/logo.png">

This automatically uses the current protocol.

✅ 3. Use a Search and Replace Plugin (WordPress)

Plugins like Better Search Replace or Velvet Blues Update URLs can help bulk replace all http:// links in your database with https://.

✅ 4. Update Theme and Plugin Files

Check your theme’s header.php, footer.php, or custom JS/CSS files for hardcoded HTTP links and update them.

✅ 5. Use HTTPS-Enabled External Resources

If you’re linking to external scripts or stylesheets (e.g., fonts, libraries), make sure they’re available over HTTPS. If not, consider hosting them locally.

✅ 6. Enforce HTTPS via Content-Security-Policy (CSP)

You can set a CSP header to upgrade all HTTP content:

Content-Security-Policy: upgrade-insecure-requests;

🚀 Preventing Mixed Content in the Future

Always use HTTPS for internal and external resources.
Enforce HTTPS with an .htaccess rule or server-level redirect.
Install and configure an SSL plugin (like Really Simple SSL) in WordPress to automatically fix mixed content.
Regularly monitor your site for new issues after updates or changes.

🧩 Related Articles

Mixed content errors are not just minor annoyances—they’re critical for site security and SEO. Resolving these issues ensures that your visitors have a safe experience and helps maintain your credibility in the eyes of both users and search engines.