These days browsers are shipping with a their own PDF viewing software so you don’t have to install a third-party plugin. Firefox uses PDF.js, Chrome and Opera includes their own PDF plugin, Safari uses Preview and Microsoft’s new browser, Edge, even ships with a document reader. This is great in theory, but in practice it causes problems. Why? Because building software that correctly renders PDFs is hard (just take a look at the latest PDF specification and tell us it doesn’t give you a headache). And if that’s not a compelling enough reason check Firefox’s PDF.js current open issues…
In some browsers you’ll be able to install an Adobe Reader add-on and change the default PDF viewer. But if you cannot install the add-on, and you want to ensure a consistent viewing experience, your best option is to save any PDF documents to your computer and open them with Adobe Reader.
