SEO Optimization of PDF Files

Lay a solid foundation for searchable PDF files

For a keyword analysis

When it comes to SEO optimization of PDF files, just as with regular web pages, it’s important to start by conducting keyword research. Once you know which keywords have good search volume and are relevant, you can begin with the basics of PDF optimization.

With these alternatives to the Google Keyword Planner tool, you can easily find the keywords that are relevant to you.

Choose the correct file name

Specifically, choosing a filename that’s search engine-friendly. Also pay attention to the length of the filename; ideally, make sure your PDF filename consists of no more than 5 words. Use a hyphen (-) to indicate a space between two words.

Enter a title and meta description

After the file name, move on to the title and meta description. Optimize these for search engines as well. It’s important for the user to know right away what information is contained in the PDF file.

You should choose the title and meta description of your PDF carefully—not only for that reason, but also because it’s important that they be unique. They must not match the title or meta description of any other web page. Search engines may interpret this as duplicate content.

Setting a meta title and meta description

You can easily set the meta title and meta description using various PDF editing programs. For this example, we are using Adobe Acrobat Reader. Once you have opened the PDF file, go to File.> Properties (English: File> Document Properties).

Enter the Title and Subject here. The Title field corresponds to the title of a web page, and the Subject field corresponds to the meta description.

Use a logical heading structure

Be sure to use a good heading structure as well. This makes it easier for readers to skim through your PDF. Search engines also value good headings; they use them to determine the content and hierarchy of the PDF file.

Give your PDF file credibility

The same applies to PDF files: they’ll be easier to find in search engines if you boost their authority through backlinks and link building. So be sure to include relevant backlinks in the PDF document. And, of course, it’s also a good idea to include internal links. Just make sure the link structure looks natural.

So, identify which pages on your website are relevant for linking to and factor in your keyword analysis. Keep in mind that the deeper you link within the site structure, the less authority the link will carry.

Avoid duplicate content

We just mentioned it briefly: duplicate content. Google considers this “duplicate content” undesirable. Therefore, the content in your PDF must not be a copy of content you publish elsewhere.

Sometimes it’s simply not possible to avoid duplicate content. In that case, the canonical URL —in the form of an HTTP header—prevents Google from treating your PDF as duplicate content. The canonical URL points to the original file, ensuring that only one page is indexed.

Example of an HTTP “canonical” header

HTTP/1.1 200 OK
Server: nginx
Date: Fri, 9 Jul 2019 14:32:51 GMT
Content-Type: application/pdf
Content-Length: 1025
Last-Modified: Fri, 9 Jul 2019 14:32:51 GMT
Link: ;
rel="canonical"

Please note the file size

Also, keep an eye on the size of your PDF file. For example, if you add a high-resolution image, you can quickly exceed the maximum recommended file size of 5 MB.

Large files negatively affect the loading speed of your PDF file, so a long loading time leads to a lower ranking. You can reduce the file size by compressing images before adding them to a PDF file.

You can also use various programs to adjust the quality of a PDF file. Setting a lower quality will result in a smaller PDF file.

Here’s how (not) to save your PDF file

It’s often possible to save a PDF file as an image. This prevents the text from being selectable, which significantly affects the discoverability of your PDF file.

In that case, search engines will have a harder time identifying the content of your PDF, which means your PDF file won’t be easy to find. Therefore, make sure to save the PDF file with text content.

Optimize your PDF for mobile devices

Your PDF file will be viewed on various (mobile) devices. Unlike websites, it is not possible to make your PDF files responsive.

Therefore, avoid making the reader scroll unnecessarily on a mobile device to read the PDF file properly. Aligning text to the left and placing images above the text prevents unnecessary scrolling.

Conclusion on Optimizing PDF Files

So, if you optimize your PDF files properly for SEO, you’ll increase your chances of generating additional traffic and revenue. By following the SEO tips above, you’ll lay a solid foundation for the discoverability and optimization of your PDF files.