A Simple Test
Try to copy the text of your PDF file and paste it into a Word document. If it looks just like you see it in your PDF file, the document is fully accessible and you’re good to go.
- Accessible Sample (PDF, 12 pages)
It’s easy to select and copy the text from this PDF, and it looks exactly the same when pasted into Word.
- Inaccessible Sample A (PDF, 47 pages)
You can’t even select the text to copy it.
- Inaccessible Sample B (PDF, 48 pages)
You can copy the text—it’s been “captured” with optical character recognition (OCR), but if you try pasting it into Word you’ll see it’s not quite right; it hasn’t been proofread.
If Your Text is Not Accessible
OCR with Windows and Office (PDF) is a wonderful step-by-step guide (with pictures) to taking an inaccessible PDF file to a fully accessible text document using Acrobat Reader (the free PDF viewer) and Microsoft Office tools.
You can also upload the PDF to Google Drive, then open it with Google Docs. Google will attempt OCR on the PDF, and you can proof-read the resulting text.
Images, Charts, and Graphs
Remember to provide text-only descriptions of any information conveyed through images or color so that people who can't see (or can't see well) can still understand your document.
Users Don't Like PDFs
A great side effect of this procedure is that you'll have a plain text version of your document, ready to be republished in any other format, including as a plain ol' user-friendly and search engine optimized web page or site.
Jakob Nielsen, web usability expert, has put together some compelling points about how PDFs are good for printing, but not for online consumption.
In addition, PDFs are not search-engine friendly: Just Say No to Adding More PDFs to Your Website.
Acrobat Reader is a Vulnerable Application Targeted by Malicious Users
In 2011, a total of 35% of all exploit-related incidents targeted vulnerabilities in Adobe Acrobat Reader.
You can reduce your risk by using a less-targeted application like Nitro PDF Reader, but be aware that people who have heard that "PDF files are unsafe" may be wary of clicking on links to your PDFs.