Compared to LaTeX, HTML may be a little weak in typesetting for paged output. However, it is much more powerful in presenting results, especially when combined with CSS and JavaScript. For example, you can embed interactive applications in HTML, and dynamically modify the appearance and even the content of an HTML page. Some useful yet simple CSS and JavaScript tricks for HTML output are very difficult (and often impossible) to reproduce in LaTeX output.

In this chapter, we introduce techniques to enhance your HTML output from R Markdown, including how to apply custom CSS rules, use custom HTML templates, style or fold code blocks, arrange content in tabs, and embed files on HTML pages.