Which format for API documentation programmers prefer: PDF or Web?
My answer to Which format for API documentation programmers prefer: PDF or Web? on Quora
HTML is a better format for documentation than PDF.
Documentation needs to be easy to access, easy to bookmark, easy to share links to and easy to copy and paste from.
PDFs are lousy for linking to (you can link to the whole document but not to individual sections) and frequently cause weird issues when copy and pasting.
The two advantages of PDF are that you (the author) get more control over how it prints and it’s easier for the end user to download as a single file for offline reading.
If you think these issues are important to your audience you can solve them with HTML by including a good print stylesheet and a zip file for download of all HTML and assets. You could also use a documentation system such as http://sphinx-doc.org/ which can generate both HTML and PDF versions.