July 25, 2020

Adding Tailwind CSS to Rails 6 Project

I have just started really exploring Tailwind CSS and so far, love just how customizable things are. In contrast, with Bootstrap or any other framework, you would likely need to write several custom classes to get what you want. But even the default setup for Tailwind provides a plethora of options for you to customize away without writing any CSS, but rather just attaching classes in your HTML as needed.

I have seen a few different ways to get Tailwind into a Rails 6 project but this is the way I settled on and found easiest. I have included it to run via Webpacker rather than the asset pipeline. I have read in a few places that it's likely that future versions of Rails won't even include the asset pipeline, so besides the efficiency alone of Webpacker, it's probably a good reason to start using it completely now. So let's do this.

Add Tailwind to your project via Yarn

yarn add tailwindcss

Update Your PostCSS Config File

In the root of your project is a file called postcss.config.js. That will need to be updated like below. This tells Rails to require Tailwind CSS and where it is coming from, which we will set up after this to run via Webpacker.

module.exports = {
  plugins: [
    require('tailwindcss')('./app/javascript/stylesheets/tailwind.config.js'), #Added Line
      autoprefixer: {
        flexbox: 'no-2009'
      stage: 3

Add Tailwind Components to work with Webpacker

Next, navigate to app/javascript folder in your project and create a folder called stylesheets. You could also do this in Terminal.

# make directory called stylesheets in app/javascript folder
my-project $ cd app/javascript
my-project/app/javascript $ mkdir stylesheets

Then make a file called application.scss inside the stylesheets folder. This can be done in the editor of your choice or as before, you could use Terminal like below.

# inside your project folder
cd app/javascript/stylesheets
touch application.scss

Get the default Tailwind Config File into your project

This is where all the default styles/classes are defined in Tailwind. The easiest way to do this is through the terminal with node js. Be sure you are in the stylesheets folder as you were above.

# Terminal inside app/javascript/stylesheets folder
npx tailwindcss init --full

That should create your tailwind.config.js file with all the base styles inside your stylesheets folder.

In the application.scss, you then need to import Tailwind.

# app/javascript/stylesheets/application.scss
@import "tailwindcss/base";
@import "tailwindcss/components";
@import "tailwindcss/utilities";

Now, we need to make sure the application.js imports all the Tailwind to allow Webpacker to do its thing. Look in the app/javascript/packs folder for the file application.js. Update that file as such:


import "stylesheets/application"; # Added this line where Tailwind CSS is

The last thing you will need to do is add a stylesheet_pack_tag to your layout file.

 <%= stylesheet_pack_tag 'application', 'data-turbolinks-track': 'reload' %>

In your application layout file, it would look like this included between the stylesheet_link_tag and the javascript_pack_tag.

<!DOCTYPE html>
    <%= csrf_meta_tags %>
    <%= csp_meta_tag %>

    <%= stylesheet_link_tag 'application', media: 'all', 'data-turbolinks-track': 'reload' %>
    <%= stylesheet_pack_tag 'application', 'data-turbolinks-track': 'reload' %> // Added this line
    <%= javascript_pack_tag 'application', 'data-turbolinks-track': 'reload' %>

    <%= yield %>

Then you should have Tailwind working. Be sure to restart your server in development if needed to reinitialize Webpacker.

Optional: Add Custom Components

One thing I picked up while taking the Hello Rails master class (which I highly recommend), is that you will want to also make it possible to create your own custom components at some point too. So let's set that up as well.

In the stylesheets folder, create another folder called components. Inside that folder you can create custom components. Each file there would have the extension scss. For example, you may want to create a custom icons component with predefined classes for icons. In this case, you could create a file called icons.scss inside your app/javascript/stylesheets/components folder. It could look like this:

# app/javascript/stylesheets/components/icons.scss

.icon-sm {
    width: 16px;
    height: 16px;

.icon-md {
    width: 24px;
    height: 24px;

.icon-lg {
    width: 64px;
    height: 64px;

Now you pull that component and its classes simply by importing to you application.scss file in the stylesheets folder like such:

// app/javascript/stylesheets/application.scss

@import "tailwindcss/base";
@import "tailwindcss/components";
// Add custom components
@import "components/icons";  // added custom icon component
@import "tailwindcss/utilities";

Once again, I learned the bulk of doing it this way through the Hello Rails course. Check it out if you want to take your Rails and design game to the next level.