SEO For PDFs: Optimizing Your Website’s PDF Files for Increased SEO
Updated: 04/08/2020
While most search listings on Google consist of traditional HTML and HTM files, the Mountain View company indexes dozens of other file types, including Portable Document Files (PDFs). Developed by Adobe in 1993, PDF is a PostScript-based file format that supports text and images. PDFs receive their namesake from their portable design, meaning they work on all devices as well as all major operating systems and web browsers. When uploaded to a website, visitors can load PDFs just like a regular web page.
To see examples of PDFs in Google’s search results, use the file type operator “filetype:PDF.” For mortgage-related PDFs indexed by Google, for instance, search for “mortgage filetype:PDF.” You should see more than 30 million results of PDFs about mortgages. Google indexes and displays PDFs for conventional search queries, but using the file type operator is a quick and easy way to see these files in Google’s search results firsthand.
Search engine optimization (SEO) requires a different approach for PDFs than HTML and HTM web pages. Since there’s no HTML code, you must optimize other elements of your website’s PDFs. With the right SEO strategy, though, Google, Bing and other search engines will rank your website’s PDFs higher in their search results.
Add Metadata
PDFs support metadata that search engines crawl and use to create listings for PDFs and determine their search rankings. With your PDF open, click File > Properties or use the Ctrl + D shortcut command to access the document’s metadata. On the Description tab, you’ll see several fields, the two most important of which are Title and Subject.
The Title field represents the title of your PDF, which search engines treat like the title tag for traditional web pages. The Subject field, on the other hand, is the equivalent of the meta description element for traditional web pages. Therefore, these two fields will determine the way in which PDFs are displayed in the search results.
For the Title field, enter a 50- to 60-character title describing the document’s content. For the Subject field, enter a 250- to 300-character summary of its content. In both fields, include the primary keyword for which you want the PDF rank.
Use a Keyword-Rich File Name
To optimize your PDFs for higher search rankings, give them a relevant, keyword-rich file name. PDFs are often created with a generic, nondescript file name containing a combination of random letters and numbers. Search engines won’t learn anything extra about your PDFs if the documents have a generic name such as this.
The file name is also used to form the URLs of web-based PDFs. After uploading a PDF to your website, the URL on which it’s accessible will consist of your domain name, subfolder names, if the PDF is uploaded to a subfolder rather than root directory of your server, and the PDF’s file name. By using a keyword-rich file name, you’ll create an attractive URL slug for your PDFs while providing search engines with ranking signals in the process.
You can rename PDFs either by opening and saving them with a different name or by right-clicking the file in the macOS or Windows and choosing the rename option.
Create Unique Content
Don’t copy large amounts of content from other pages on your website or any other website to use in a PDF. If a PDF consists primarily of content found elsewhere on the internet, it won’t rank high in the search results. Instead, Google will prioritize the original web page on which it was published.
Google won’t penalize your PDFs if they contain small amounts of duplicate content. Adding your business’s slogan or a quote from an industry expert, for example, won’t impede your PDF optimization efforts. You should, however, aim for at least 90 percent unique content when creating PDFs.
Add Headers
Including headers in your PDFs allows visitors to scan content for key points rather than reading it word for word. Without headers, your PDFs will look like a large block or wall of text, which will likely discourage visitors from reading it. As search engines discover visitors are quickly exiting out of your PDFs, they’ll knock down your PDFs’ search rankings.
To add headers to a PDF, open the document in Adobe Acrobat and select Tools > Edit PDF. In the toolbar section, click Headers & Footers > Add.
Don’t Display Text as an Image
Adding images is an excellent way to visualize content in PDFs, but you shouldn’t use them as a substitute for text. Countless PDFs feature screenshots of text rather than actual text. Google’s algorithm has come a long way since it began indexing PDFs in 2001, yet it still struggles to crawl and understand images. To assist Google in crawling your PDFs, avoid displaying text as an image.
Shrink the File Size
The file size of your PDFs can affect their search rankings. The larger a PDF’s file size, the longer it will take visitors to load. Google and Bing have publicly stated that fast-loading pages are given priority over slow-loading pages in their search results.
To reduce the file size of your PDFs, limit your use of images. Images account for a significant amount of a PDF’s total file size. Using fewer, smaller images allows you to create PDFs with a smaller file size that load quickly. You can also compress your PDFs using an online tool like pdfcompressor.com or smallpdf.com/compress-pdf.
PDFs support web optimization to further reduce their load times. Using this feature won’t reduce the file size of your PDFs, but it will allow visitors to load them more quickly. To optimize your PDFs for online viewing, open them in Adobe Acrobat and select Edit > Preferences. Next, tick the box titled “Save As optimizes for Fast Web View,” after which you can click “OK” to save your changes.
PDFs are just one of many alternative file types indexed by Google. Others include SWF, PS, DWF, GPX, DOC, DOCX, ODP, ODS, and ODT. With PDF being such a widely used format for documents, though, PDFs are found more frequently in Google’s search results than other non-HTML files. By adding SEO for PDFs, you’ll encourage search engines like Google to rank these documents higher in the search results, thereby driving more organic traffic to your website.
