With the installation of SSL certificate, your WordPress website changes from HTTP to HTTPS, although it doesn’t ensure the change in all resources used on your website. Thus, it is possible for you to face the problem of WordPress mixed content because some resources will be loaded via HTTP protocol.
This will result in browser warnings for security, blocking of resources, or failure of some parts of your website. Luckily, mixed content errors are mostly caused due to obsolete URLs and configuration problems and can be corrected without any need of reinstallation of WordPress.
Here you will be guided on how to detect and fix mixed content errors after SSL installation.
Table of Contents
What Is Mixed Content in WordPress?
Mixed content refers to loading a page using a secure HTTPS protocol while trying to load certain files over an unsecured HTTP protocol.
For instance, you may have your home page URL like:
https://example.com
while your image link on that home page would be:
http://example.com/wp-content/uploads/image.jpg
The webpage uses HTTPS protocol in general, but the browser is being instructed to load a portion of it using HTTP protocol. Depending on what resource it is, the web browser can block it or show the security warning to the user.
Common Causes of Mixed Content errors
Some of the common causes for the mixed content errors are:
- Images/Videos
- CSS files
- JavaScript files
- Web fonts
- Embedded media
- Theme files
- Plugins-generated resources
- Links saved in the WordPress database
This is the reason why having an SSL certificate may be insufficient in solving all the issues that relate to HTTPS.
Why Do You See Mixed Content in WordPress After Installing SSL?
The major cause is that there are some URLs on your website which were created before SSL installation.
For instance,
http://example.com/wp-content/uploads/2025/06/image.jpg
This is a link of an old image which may cause mixed content in WordPress after installing SSL.
But old HTTP URLs might be found in:
- WordPress database entries
- Theme files
- Post and page entries
- Plugin configuration options
- Widgets
- Media URLs
- Menus
- Custom CSS
- Third party resources
As a consequence, users might visit the home page via HTTPS, whereas particular resources will be accessed using HTTP.
How to Fix WordPress Mixed Content Errors After Installing SSL
1. Ensure That Your SSL Certificate is Operating Correctly
Before you begin troubleshooting your mixed content issues, you must ensure that the SSL certificate is functioning properly.
Open your website from the following link:
https://yourdomain.com
as opposed to:
http://yourdomain.com
The website should open for you without any warning message regarding the certificate.
In case your browser gives you a warning about an invalid, expired, or improperly installed certificate, fix that issue first. The Beginner’s Guide to SSL Certificates by HarmonWeb describes what SSL certificates are and how they function. Even if your SSL certificate is not properly configured, solving the individual URLs will not be enough.
2. Verify Your WordPress URL Settings
The first setting that you need to check in WordPress is the Website URL.
The process for checking WordPress URLs is done by logging into the WordPress dashboard and selecting Settings > General from the menu. In this case, users need to ensure that the WordPress Address (URL) and Site Address (URL) contain the right domain name and https:// protocol.
For instance:
WordPress Address: https://example.com
Site Address: https://example.com
In case one of them is using http://, change it to HTTPS.
Beware while doing so, as entering wrong domain/URL may keep you out of your WordPress Dashboard.
3. Locate HTTP URLs on Your Website
Modifying WordPress URL settings doesn’t automatically change all the old HTTP URLs stored in your database.
An image may be called using:
http://example.com/wp-content/uploads/2026/08/photo.jpg
even if you have an HTTPS website. The following URLs have to be identified and replaced by their corresponding HTTPS URLs. To discover and to fix the HTTP URLs in your website that are insecure, there are some tools like plugins or website crawlers that you can use.
This is especially critical after:
- Installation of SSL
- Website migration
- Domain change
- HTTP to HTTPS upgrade
- Restore of an old website backup
The HarmonWeb domain redirection techniques article mentions that when upgrading from HTTP to HTTPS, internal links and canonical URLs among other website URLs should be updated.
4. Use a Search-and-Replace Tool Wisely
When you have to work with hundreds or even thousands of HTTP URLs in your database, doing it manually would waste a lot of your time.
With a search-and-replace tool, you can find all the places where you have:
http://example.com
and replace it with:
https://example.com
This method has been suggested by HarmonWeb to change HTTP URLs in the WordPress database. Ensure that you have a backup copy of your site before making any replacement on the whole database.
The reason is that a wrong search-and-replace tool may affect more URLs than desired. It’s best not to simply replace all instances of “http://” with “https://”, especially when there are legitimate external sources that do not use HTTPS.
5. Examine Images That Continue to Use HTTP
Image files are one of the most common elements that can be a source of mixed content problems. This process can be achieved either by utilizing your browser’s internal developer inspection features or by conducting a dedicated scan on the website itself.
Identifying HTTP Images on Your Web Page
- Using Browser Developer Tools: Just open your website page, hit F12 (or you can just right-click and select “Inspect”). After that, go to Network Tab, reload the page, and filter the page by “Img” to see all links that begin with http:// rather than https://.
- WordPress Plugins/Scanners: Install a site inspector plugin or use a database scanner such as HarmonWeb’s Guide to Common SSL Problems.
Steps for Resolving HTTP Images
- Fix Site URLs: Make sure that your WordPress URL and Site URL are set as https:// on your dashboard.
- Search and Replace within the Database: Perform a database search and replace using plugins such as Better Search Replace for all your http:// images with https:// images in your database.
- Install an SSL Plugin: Use plugins such as Really Simple SSL for converting all insecure media elements into HTTPS.
A database replacement might be considered in case there are numerous affected pictures. This is important in relation to web site performance as well. HarmonWeb provides advice on image optimization in order to improve SEO performance.
6. Verify Your Theme and Plugins
The HTTP URL may not be part of a post or page.
It can be created by a theme or plugin.
Common instances are:
- Logos
- Background images
- CSS styles
- Javascript files
- Font files
- Slider images
- Analytics tracking
- Content Delivery Network (CDN) resources
If the “Mixed Content” warning came up right after you installed or configured a plugin, then just disable the plugin to check your website. You may also test to see if the error is solved by changing to the default WordPress theme on a temporary basis.
If the error gets solved, you have pinpointed the problem.
7. Check Your Browser Developer Tools
If you are having a problem identifying the remaining insecure resource, the developer tools of your browser can help.
In Chrome and other Chromium browsers, open the webpage and check the Console.
Warnings will be listed regarding:
Mixed Content
This warning usually shows the URL of the HTTP resource being loaded by the browser. After establishing the exact source, you are now able to check whether it is sourced from:
- WordPress article
- Stylesheet
- Theme
- Plugin
- External services
- Image
This is usually more efficient than trying to figure out where in the website the content comes from.
Can There Be any Effect of Mixed Content on SEO?
The problem of mixed content is basically a security and functionality issue; however, it could also impact the user experience of the website, indirectly.
For instance, the browser might block the insecure scripts or other items and thus make some functions of the site not work anymore. Hence, after SSL installation, do not just rely on your browser displaying the padlock. Ensure that the whole page and its resources are indeed served over HTTPS.
How to Prevent Mixed Content Issues in the Future
After you have made your website HTTPS ready, don’t ever take the website back.
- Don’t add HTTP resource references manually in code.
- Update WordPress and plugins.
- Check SSL certificates status and expiration dates.
- Regularly back up the website.
- Use HTTPS always while creating internal links.
When transferring your site to a new server, be sure to check SSL settings and URL once more. This has been emphasized by HarmonWeb’s website migration checklist that lists SSL settings and configuration as key elements of website migration.
Conclusion
WordPress mixed content problems arise because some of the site’s resources continue using HTTP even after installing the SSL certificate. Ensure that you verify your WordPress URL and upgrade all HTTP resources. Also, consider the plugins and themes and flush your cache.
Should the issue persist, it could be an SSL or hosting problem.
Having Trouble with Mixed Content?
A correctly set up SSL certificate and WordPress hosting can be a solution to your issues. HarmonWeb is offering WordPress hosting with SSL enabled, helping to make sure that your website works smoothly.
Transfer your WordPress site to properly configured hosting at HarmonWeb.
