All these PDFs need to be converted. What happens between when you convert them to HTML and when you display them? In principle, HTML has a fixed width. If a PDF is larger, or if the browser doesn’t have the proper font for the content type, it may result in the document becoming unusable. You can make a few different decisions in order to optimize the rendering. You'll have to decide a certain width and make sure the user is not able to scroll by too much during the conversion process, or the content may be lost. You only want to display the best result possible in a responsive manner. If there's space between paragraphs in the PDF, it may be necessary to display them as table in the HTML text. If you have to change the fonts, change them in the markup and in the font.css file that.