PDF files are part and parcel of online courses through various learning management system courseware plugins like Learndash ,Learnpress, Sensei LMS or LifterLMS etc. Various kinds of helpful educational content are provided to students who have paid for a course. But it may just happen that the course materials in PDF format that is otherwise available to only paid members appear in Google search, and anyone clicking the link for the PDF may download it. So, the issue of PDFs from your WordPress LMS course appearing in Google search results is indeed a security concern.
Here are a few solutions to prevent unauthorized access to your restricted PDFs:
1. Stop PDF files to be Indexed Through Robots.txt File
The first line of defence is to disallow search engines from indexing your PDF files. You can modify the robots.txt file in your website’s root directory. Add the following line to the robots.txt file:
User-agent: * Disallow: /path/to/your/pdf/
Remember to replace “/path/to/your/pdf/” with the actual path where your PDFs are located. However, this method isn’t foolproof, as some search engines might ignore the robots.txt directives.
Use a WordPress Plugin
Numerous WordPress plugins can prevent your PDFs from being indexed by search engines. Plugins like “Search Engine Visibility” or “Yoast SEO” can help you set up “noindex” tags for specific resources like PDFs.
Move PDFs to a Secure Location
Another way to prevent your PDFs from being found through Google search is by moving them to a secure location or a different server. This could be a password-protected directory or a server-side protected directory. Only the users with the correct permissions can access the files in these locations.
Password Protect Your PDFs
You can add an additional layer of security by password-protecting your PDF files themselves. There are a number of tools available that can do this, including Adobe Acrobat.
Use a Document Security Plugin
There are specific WordPress plugins available like “Prevent Direct Access” or “WP Content Copy Protection” that prevent users from directly accessing and downloading your PDFs.
Use a Secure PDF Embedding Plugin
Consider using a plugin like “PDF Embedder Secure” that provides a secure way to embed PDFs into your courses. The plugin ensures that PDFs are not stored in a simple way on your server and cannot be located with a simple Google search.
Finally, after implementing these changes, you might want to request Google to de-index the already indexed PDF files. You can do this through the Google Search Console.
Remember, security is a layered approach, so consider combining these methods for better results.