This web app takes plain HTML/CSS and converts it into a single HTML file with tailwind classes (version 3.4.1). Documentation regarding currently supported classes can be found here.
It's also important to keep in mind that converting an existing project to use Tailwind CSS often involves more than just replacing classes. It may be best to restructure your HTML and/or adjust your design to match the available utility classes. Manual conversion would provide more control over the process and likely ensure a better end result.