pdf.js was quite slow when it was first released. But have you tried it lately? It's a lot faster and less memory-hungry than it used to be. E.g. see https://bl

pdf.js was quite slow when it was first released. But have you tried it lately? It's a lot faster and less memory-hungry than it used to be. E.g. see https://blog.mozilla.org/nnethercote/2014/02/07/a-slimmer-and-faster-pdf-js/ https://blog.mozilla.org/nnethercote/2014/02/07/a-slimmer-an... and https://blog.mozilla.org/nnethercote/2014/06/16/an-even-slimmer-pdf-js/ https://blog.mozilla.org/nnethercote/2014/06/16/an-even-slim..., and there are plenty of other optimizations have occurred as well. It's PDF conformance has also improved greatly. It's still not as fast as a native PDF reader, and probably never will be. When I'm dealing with really large PDFs (e.g. the Intel x86 docs, which are 1000+ pages) I still use a native PDF reader. But I find that pdf.js does just fine on documents of up to a few hundred pages. Which is, y'know, most of them. And having PDFs open in the browser is so convenient -- I get a happy feeling every time I open a PDF and I don't get a dialog asking me to save this file and/or open it in an external application.