Back in the day, there was a long-held belief that Google found PDFs impenetrable.
That myth has since been unceremoniously busted by Google in 2011 when they announced that:
“Google first started indexing PDF files in 2001 and currently has hundreds of millions of PDF files indexed.”
They even come with their own tag in SERPs to alert users that the result is PDF-based:
Today, search engines are indexing PDFs and even including them as featured snippets:
— Kevin_Indig (@Kevin_Indig) January 16, 2019
This opens up a growing opportunity to increase traffic with existing and new PDF content across your site.
But, you’ll need to follow these 13 SEO optimization tips for PDF files to have the best chance of ranking.
When Should You Use a PDF?
PDFs (which is short for portable document formats) are often used for content that requires extra effort to create, and you may want people to be able to print your content to your exact specifications.
Ebooks often have illustrations, infographics, and guides.
You can also include cover art, headers, and footers, making your ebook even more like a book.
If you have content that benefits from an offline option, then PDFs are a preferred route. This goes for info heavy blog posts as well.
Although, you’ll want to make sure the PDF version of your blog posts isn’t indexable to avoid being penalized for having duplicate content.
Often format heavy and with an abundance of images and illustrations, PDFs are an ideal format for specification documents.
Given how often specification documents are printed, a PDF ensures that everyone sees your document in the same way.
Often longer than most online content, PDFs are good for white papers.
Given how often people make notes on white papers, it’s good to offer a printable option.
You want to make sure your PDF contains links to the rest of your website.
Otherwise, you’ll be jeopardizing your click-through-rate (CTR), which might compromise your ranking since the algorithm factors how much time is spent on your website and how much of your website users explore.
You may even consider offering an HTML version of your PDF, make your PDF unindexable, and instead offer the option to download your PDF.
The option to download a PDF is also a great opportunity to get a visitor’s contact information.
Simply offer the PDF as something that will be emailed to your users in exchange for their name, email, etc.
How to Make Your PDFs SEO-Friendly
Optimization for PDFs follows much of the same best practices as “traditional” SEO.
However, the details differ in some crucial ways, which are outlined below.
1. Compress Your PDF File to Reduce File Size
Most importantly, make sure your file is not already optimized for speed.
Check If Your PDF Is Optimized
Similar to a webpage, reducing a PDF’s file size is paramount.
Make sure your PDF is optimized for the web.
Luckily, this is an easy process:
Optimize PDF Fonts
PDF readers support a set of standard fonts:
Any other fonts will likely have to be embedded, and that increases your file size.
You can choose not to embed any fonts, but then Adobe Acrobat will substitute a standard font for you.
Because a major appeal of PDFs is the granular control the format affords you, you’re going to be missing out on one of the main reasons to use the format in the first place if you give up font control to Acrobat itself.
So, use the standard fonts.
Use Fewer Fonts
Every font you use just makes your PDF bigger, so use fewer fonts!
Use Less Font Styles
Every font style you use is treated as a different font, which, you guessed it, increases the size of your PDF.
So, keep that in mind when making your font decisions.
To see whether your fonts are embedded, follow this procedure:
Optimize PDF Images
Use Vector-Based Images
Vector-based images are smaller and of higher quality than bitmap images.
Use Monochrome Bitmap Images
If you must use bitmaps, make them monochrome and not color to ensure they’re as small as can be.
Optimize Microsoft Word PDFs
You can reduce the size of your PDF when exporting your Word document by following these steps:
Optimize Your PDF with Adobe Acrobat
You can further optimize your PDF using Adobe Acrobat.
You’ll have a variety of options including standard mode, mobile mode, or you can customize your presets.
Note: If you change your preset standard options, that the settings will automatically change to custom.
For further information about all these settings, see Adobe’s tutorial on optimization.
You’ll want different settings based on each type of PDF you create (image-heavy vs. text-heavy).
Fast Web View
Fast Web View restructures a PDF to download one page at a time.
This is useful when your PDF is a big file (remember, long load times may inspire someone to bounce).
Follow these steps to turn on Fast Web View:
Initial View Settings
Adobe also lets you control how your PDF will appear as soon as it’s opened.
You can toggle:
2. Keyword-Rich File Name
Treat your file name like you would a URL or H1.
That means making your file name keyword relevant and search-friendly.
While your Google Doc may be called SEO Best Practices, your PDF file name should be: seo-best-practices.pdf.
Here are a few file naming best practices:
3. Body Copy
One of the reasons that those myths persisted for so long about Google and its PDF problem was that so many PDFs are image-based.
If you want your PDF to be indexed in and of itself, then make sure it has more text than images.
Not sure if your PDF is text or an image?
If you can copy and paste the text from the PDF, it is in text rather than an image format.
Luckily, many common tools, including Adobe’s own Creative Suite, will allow you to make this conversion easily.
Here are some general best practices when writing for the web:
4. Heading Tags
PDFs can contain lots of in-depth information so content should be broken up with subheadings.
Here are some general best practices for assigning heading tags to your content:
5. Use Alt Text For Images
Alt text is text that appears in place of an image on a website in the event that the image doesn’t load.
Alt text is important because it:
To use alt text, do the following:
The key to writing alt text is to be:
6. Set Reading Language
To set the reading language, open the Document Properties dialog:
7. Create an Optimized Title Tag
PDF properties are the PDF version of a webpage’s metadata.
To edit the properties of your PDF do the following:
The title field should be treated as you would treat the title tag of a webpage.
Here are some general guidelines to use when crafting title tags:
8. Meta Description
To edit the meta description properties of your PDF do the following:
Here are some general guidelines for adding a meta description:
9. Internal Linking
Make sure that your PDF contains links to other pieces of your content, and to use anchor text best practices.
Your anchor text should be:
If your PDF is meant for off-line consumption, you should use the link URL instead of or in addition to the linked keyword text.
That way readers can visit the desired website later if they want to.
10. Use Older Versions of Acrobat
When saving your PDF, make sure to use an older version of Adobe Acrobat to avoid compatibility issues between your readership and potentially even search engines.
11. Link to Your PDF
Make sure to link to your PDF on your own pages using SEO best practices as well.
12. Make Your PDF Mobile-Friendly
So much content is consumed on mobile devices these days that to not optimize your PDF for a phone, tablet, etc would be a big mistake.
If enough people find your not-mobile friendly PDF and then bounce, that will adversely affect your page rank.
So, follow these steps:
13. Track PDF Downloads
Given the uses of PDFs, you may want to track them individually as an end unto themselves.
You can, for example, see how many people got to your website using organic search and then downloaded your PDF.
You can also see which other nooks and crannies of your marketing strategy were interacted with on the way to downloading the PDF.
Summary: PDF SEO Best Practices
Google knows PDFs can be useful.
That’s why Google indexes PDFs and turns some of them into featured snippets.
You should treat your PDFs with the same degree of reverence as Google does.
By using the aforementioned tips, you’ll make it easier for both Google and your users to find and rightfully appreciate your work.
All screenshots taken by author, September 2020