I spent a little time today researching how to optimize PDF’s for the search engines. I’ll summarize what I found – but note that this isn’t a complete list, there are a number of other techniques out there.
1) All three major search engines can crawl PDF text – just make sure the file is created in a text-based application like Acrobat or Word. PDF’s created from Photoshop files are not text-based.
2) Create links within the PDF’s content just as you would for a regular web page.
3) Most search engines (including Google) will pick up and use a title element as the title for their results pages, so this is important! To enter a title phrase, click File > Document Properties.
4) If you don’t include a title, Google will instead pull up the first chunk of text it finds in the document itself and use that as the title for the document it its results pages. This can have unwelcome consequences, as you might imagine, so take a moment and put in a real title phrase.
5) Some search engines will pick up the description element (Yahoo will, but Google won’t from what I read today) so it probably doesn’t hurt to enter something here.
6) When finished editing existing PDF’s, click Save As… to save over the existing file and clean up any unused objects.
A few articles about optimizing PDF’s for the web:
How to Optimize PDF Files for Web Sites by Andy King.
Make Your PDF’s Work Well with Google by Duff Johnson.
SEO Your PDF’s by Kevin Kantola.