Firefox has included a viewer based on PDF.js since 2013: https://github.com/mozilla/pdf.js#online-demo https://github.com/mozilla/pdf.js#online-demo No need

Firefox has included a viewer based on PDF.js since 2013: https://github.com/mozilla/pdf.js#online-demo https://github.com/mozilla/pdf.js#online-demo No need to download to anything other than localstorage. There have been a half dozen vulnerabilities found in the Firefox extension code exploitable through PDF.js over the years, but this is a far better record than the hundreds of vulnerabilities identified in Acrobat Reader. PDF.js does a lot less than Acrobat. It's much more focused on just displaying articles, and less about rich media interactions like embedding 3D models, Flash, videos, etc. in the PDF.