A recent discussion was taking place on Twitter about how Google handles PDFs in the search results, when Google’s own webmaster trend analyst John Mueller jumped in with a comment. He stated that Google is automatically reformatting PDF files into HTML in the search results, for indexing and ranking purposes. Mueller also said they convert not only PDF files but other similar files too. This includes .doc documents like Word documents, .xls spreadsheets and more similar files which do not have the HTML format.
This won’t be news to you if you keep up to date on SEO, particularly linked to PDF format. Google has been automatically converting these files for some time, and giving internet users the option to click on a HTML version displayed in the search results instead of accessing the PDF file. So this means that whilst some content creators have been working hard to perfect their PDFs, it may be that people are choosing not to access it in this form. Do note however that Google doesn’t convert the full content on larger PDF files, so if you have large PDF files, some of your important content may be missed and not indexed.
There are a few reasons why people are reluctant to open up PDF files. On some devices, such as phones and tablets, PDFs are tricky to open and require a corresponding application which can read the file for the device. They can be cumbersome to read compared to a mobile-friendly web page, and also take up much more space than if the same content were formatted into HTML. This leads to slower connection times – we all know how quickly we get frustrated when waiting for a page to load and will look elsewhere if takes more than a few seconds. For these reasons, if you have a lot of PDF files indexed, you might want to reconsider the most effective format for SEO and ranking reasons, as well as ease of user experience.
That’s not to say that PDFs cannot rank well. However, they seem to rank best when poeple are specifically looking for a PRF format, like a manual or a textbook. If your PDFs fall into this category, you might not need to make any changes at all – in fact, they may be in their best format already. However, if you do have PDFs which aren’t in this category, we’d recommend you to consider providing a HTML format instead of, or as well as, your current indexed PDFs.