September 24, 2023

Pierreloti Chelsea

Latest technological developments

What Is Mixed Content & How Does It Disrupt The Functioning of Your SSL Certificate?

Are you taking your business online? Are you trying to create a website? If the answer is yes, here is a piece of crucial information regarding website security. 

In the world of Website Hosting, when it comes to cybersecurity, buying an SSL certificate is a must. It works as a guardian that ensures secure data transmission between a user’s browser and a website’s server. 

These SSL or Comodo SSL certificates offer a robust defence mechanism against cyber threats and secure the integrity of digital communication. 

However, the smooth functionality of the SSL Certificate can be disrupted by an innocuous term – mixed content. Confused?

This article will help you understand what mixed content is and its implication for the functionality of the SSL certificate.

What Is Mixed Content?

Mixed content refers to a webpage whose elements, such as loaded iframes, stylesheets, scripts, etc., are loaded using both secure (HTTPS) and non-secure (HTTP) connections. 

  • Security Risks: Secure data might be exposed to potential attackers via non-secure resources.
  • Browser Compatibility: The browsers block non-secure resources on secure pages, resulting in broken or incomplete web pages.
  • Types: Mixed content can be either ‘mixed active content’ (scripts or iframes loaded over HTTP) or ‘mixed passive content’ (images, audio, video, or stylesheets loaded over HTTP).
  • Solution: Load all resources on secure pages via HTTPS connections and update links and references accordingly.

How Does It Disrupt The Functioning of Your SSL Certificate?

  1. Security Warning

Modern browsers often block or display warnings about mixed content. This warning informs users that the page they view is not entirely secure and their data might be at risk.

  1. Insecure Connection

Even though your page might be loaded over HTTPS, the non-secure elements are transmitted over HTTP, which attackers can intercept. It undermines the purpose of using an SSL certificate.

  1. Browser Behaviour

Browsers have varying ways of handling mixed content. Some might display warnings, others might block the content, and some might allow the content without any indication to the user. 

  1. Impaired User Trust

Seeing security warnings or mixed content on your website can erode user trust. Visitors might leave the site if they feel their data is at risk.

  1. SEO Impact

Search engines might penalise websites with mixed content. It can affect your website’s search engine ranking and visibility.

How to Prevent Mixed Content Issues?

Actions to Prevent Mixed ContentWhat Do They Mean?
Use Relative URLsUsing relative URLs for resource references enables the browser to choose the correct protocol (HTTP or HTTPS) according to the page’s protocol.
Update LinksUpdating all the resources, such as images, stylesheets, and script links to HTTPS, ensuring all content is served securely.
Update Embedded ContentEmbedding content like videos or iframes from external sources after verifying that the source supports HTTPS; if not,  find HTTPS alternatives.
Check Third-Party ResourcesVerifying that third-party resources are served over HTTPS. If they are not, contact the third-party provider to inquire about HTTPS support or seek HTTPS-compatible alternatives.
Content Delivery Networks (CDNs)Ensuring that the CDN supports HTTPS and delivers resources securely if you utilise a Content Delivery Network (CDN) for hosting resources. 


Buying an SSL certificate or Comodo SSL is crucial to ensuring online security. But having the presence of mixed content poses a persistent challenge. 

Thus, to ensure SSL security’s effectiveness, organisations must proactively identify and rectify mixed content by replacing non-secure resources with secure alternatives.