Does a PDF document stand mobile friendly? If not, Why? Michael Stebbins asked John Muller of Google by sharing a screenshot on Twitter of Google marking a PDF on his site as not being mobile-friendly.
According to John, PDFs are not mobile friendly. Though John admitted doubling check the issue, he is of the view that Google doesn’t label any PDFs as being mobile friendly.
Of course, nobody thinks that these posts require a high-level of mental effort to reach any conclusion. Thing is that PDF documents are simply not mobile-friendly. The content and images in PDF documents need pinch and zoom to see them. So they are not optimized for mobile devices.
Clearly, Google does not mark PDF documents in their search results as mobile friendly.