I've been using Tailwind CSS for a couple of years and I think it's the fastest and most convenient way of styling an app. Since I'm also very fond of ReScript I naturally want to combine the two. Luckily, adding Tailwind to a ReScript project isn't any harder than in a JavaScript app.

I've included some tools and templates in the end if you want to look at complete code or get set up quickly.

This assumes that you have an existing ReScript project where you want to add Tailwind. Start by adding the necessary dependencies, if you are using vite you won't need postcss.

npm install --dev tailwindcss postcss autoprefixer

We are now ready to run npx tailwindcss init -p, this will create two files for us:

• tailwind.config.js - A default Tailwind configuration
• postcss.config.js - A PostCSS configuration with Tailwind and Autoprefixer

To add all of Tailwind's features we create a CSS file inside the src folder with the following content.

/* index.css */
@tailwind base;
@tailwind components;
@tailwind utilities;

We then import this CSS file in our ReScript code, I usually put it in my entry file. If you use es6 output, you would add

// Index.res
%%raw("import './index.css'")

Or, if you use commonjs as your output

// Index.res
%%raw("require('./index.css')")

That should be it! webpack, vite, or whatever you use should pick up the CSS and compile all of Tailwind's classes.

Enable Tailwind's JIT compiler

Tailwind (> v2.1) includes a just-in-time compiler. It only generates the styles you use and will therefore be much faster. It also includes some nice new features like all variants being included by default and creating arbitrary styles.

The feature is still in preview, but I haven't had any major issues with it. To enable it, just add one line to your Tailwind configuration.

// tailwind.config.js
{
  mode: 'jit',
  ...
}

NOTE : Make sure that the purge setting has been added or no styles will be generated

Tools and templates

To make the process of integrating ReScript and Tailwind even easier, here are some tools and templates to help you.

• Supreme - A CLI I've written that can quickly set up a ReScript template with Tailwind (JIT and dark mode included) and Vite. Just the way I like it.
• Next.js + Tailwind - A Next.js template with Tailwind created by @ryyppy