Summary: Forcing users to browse PDF files causes frustration and slow task completion, compared to standard webpages. Use PDF only for documents that users will print. In those cases, following 10 basic guidelines will minimize usability problems.
No matter how tempting it is, you should never use a PDF to display content that users need to read online. After 20 years of watching users perform similar tasks on a variety of sites that use either PDFs or regular web pages, one thing remains certain: PDFs degrade the user experience.
Problems with PDFs
PDFs are meant for distributing documents that users will print. They’re optimized for paper sizes, not browser windows or modern device viewports. We often see users get lost in PDFs because the print-oriented view provides only a small glimpse of the content. Users can’t scan and scroll around in a PDF like on a web page. Content is split up across sheets of paper, which is fine for printed documents, but causes severe usability problems online.
PDFs also use lots of heavy, dense text and elaborate graphics which increase their file size and, subsequently, the time they take to download. They lack navigation and other interface elements that help users maintain context and move through digital content with speed and ease. The inability to navigate takes a toll on users as finding information becomes challenging and time consuming. Clickable tables of contents are often introduced in PDFs as pseudo navigation, but users still slow down and have trouble finding what they need. The use of Command or Control + F to find something within a PDF is not familiar to all users. Some users will take advantage of these shortcuts, but others won’t.