Google Search Operator – site:example.com filetype:pdf

One of the drawbacks of “inurl:” is that it will match any string in the URL. So, for example, searching on “inurl:pdf”, could return a page called “/guide-to-creating-a-great-pdf”. By using “filetype:”, you can specify that Google only search on the file extension. Google can detect some filetypes (like PDFs) even without a “.pdf” extension, but others (like “html”) seem to require a file extension in the indexed document.