【Step by Step】How to implement Dark Mode with Tailwind CSS on React

This article is also on Medium and en.taishikato.com

Taishi here👋

Today I am going to write about how to implement Dark Mode with Tailwind CSS.
Dark Mode is now one of the important features for usability and you should implement this on your website if you have not done yet.

Don't worry. It's quite easy!

BTW, the complete example on GitHub is here ✌️

taishikato / Dark-Mode-with-Tailwind-CSS

This repo is for my article: https://dev.to/taishi/step-by-step-how-to-implement-dark-mode-with-tailwind-css-on-react-3565

Create your React app with CRA CLI

$ npx create-react-app dark

Let's host it on http://local:3000

$ cd dark
$ npm run start

Now I believe you see this page on your http://localhost:3000 🎉

This time we don't need ./src/App.css, so delete the file and make ./src/App.js simpler like below😸

import React from 'react';

function App() {
  return (
    <div className="App">
      <header className="App-header">
        <p>
          Edit <code>src/App.js</code> and save to reload.
        </p>
        <a
          className="App-link"
          href="https://reactjs.org"
          target="_blank"
          rel="noopener noreferrer"
        >
          Learn React
        </a>
      </header>
    </div>
  );
}

export default App;

Now the website looks much simpler.

Add Tailwind CSS

Let's add packages for Tailwind CSS

$ npm i tailwindcss autoprefixer postcss-cli --save-dev

Generate a config file of Tailwind CSS.

The command below creates ./tailwind.config.js.

$ npx tailwindcss init

Add postcss.config.js

The content looks like this.

module.exports = {
  plugins: [
    require('tailwindcss'),
    require('autoprefixer'),
  ],
};

Make a Stylesheet file.

Let's add a ./src/tailwind.src.css like below.

@tailwind base;

@tailwind components;

@tailwind utilities;

Add a script to generate a CSS file

tailwind:css on package.json builds a CSS file as ./src/tailwind.css you actually use in your React app.

"scripts": {
+   "tailwind:css": "tailwind build src/tailwind.src.css -c tailwind.config.js -o src/tailwind.css",
     "start": "react-scripts start",
     "build": "react-scripts build",
     .
     .
     .

Let start and build use tailwind:css.

"scripts": {
  - "start": "react-scripts start",
  - "build": "react-scripts build",
  + "tailwind:css": "tailwind build src/tailwind.src.css -c tailwind.config.js -o src/tailwind.css",
  + "start": "npm run tailwind:css && react-scripts start",
  + "build": "npm run tailwind:css && react-scripts build",

Every time you use the start or build script, it generates a CSS file for you👍

Let's import tailwind.css in App.js

import React from 'react';
+ import ./'tailwind.css';

 function App() {
   return (

All set! Now your app uses Tailwind CSS 🌬️

Use Tailwind CSS to align your text

Just try to use a class text-center from Tailwind CSS. Now our App.js looks like below.

import React from 'react';
import './tailwind.css';

function App() {
  return (
    <div className="App">
      <header className="App-header text-center">
        <p>
          Edit <code>src/App.js</code> and save to reload.
        </p>
        <a
          className="App-link"
          href="https://reactjs.org"
          target="_blank"
          rel="noopener noreferrer"
        >
          Learn React
        </a>
      </header>
    </div>
  );
}

export default App;

Your web page looks like below.

Customize Tailwind CSS for Dark mode

We want to use dark: like this. In this example, when the value of prefers-color-scheme is dark, bg-black becomes valid.

<div className="dark:bg-black">

First, we need to customize tailwind.config.js to make it happen😎

Customize the screens property

Your current tailwind.config.js should look like this.

module.exports = {
  future: {
    // removeDeprecatedGapUtilities: true,
    // purgeLayersByDefault: true,
  },
  purge: [],
  theme: {
    extend: {},
  },
  variants: {},
  plugins: [],
}

Add screens property under extend.

module.exports = {
  future: {
    removeDeprecatedGapUtilities: true,
    purgeLayersByDefault: true,
  },
  purge: ['./src/App.js'],
  theme: {
    extend: {
      screens: {
        dark: { raw: '(prefers-color-scheme: dark)' },
      },
    },
  },
  variants: {},
  plugins: [],
}

What's gonna happen!?

According to the Tailwind CSS document - Custom media queries, we can make our own screen, which means tailwindcss command generates CSS like this:

@media (prefers-color-scheme: dark) {
  .dark\:container {
    width: 100%;
  }

  @media (min-width: 640px) {
    .dark\:container {
      max-width: 640px;
    }
  }
  .
  .

Let's execute npm run start again to generate a new tailwind.css and check the file 👀

It's working!

Dark Mode

Let's make your app dark mode available 😈

Just add dark:bg-black dark:text-white on App.js.

import React from 'react';
import './tailwind.css';

function App() {
  return (
    <div className="App dark:bg-black dark:text-white">
      <header className="App-header text-center">
        <p>
          Edit <code>src/App.js</code> and save to reload.
        </p>
        <a
          className="App-link"
          href="https://reactjs.org"
          target="_blank"
          rel="noopener noreferrer"
        >
          Learn React
        </a>
      </header>
    </div>
  );
}

export default App;

Now it has Dark Mode 👽

Thank you for reading.

Comments

[R Z]

This is fine, just an extra 2 MB of "CSS" code, extra work for the browser, and just making our components dependent on external CSS. In fact, this list should be longer!

[Thomas Ledoux]

You can easily purge the CSS from Tailwind. They have a whole doc section about it: tailwindcss.com/docs/controlling-f...

[R Z]

This approach has a dark side!

[Thomas Ledoux]

How so?

[Taishi]

Yes, we can easily purge the CSS 😁

[David]

If you set up PostCSS and purge correctly, there won't be any problems with CSS size. You can easily set up inlining critical CSS too to help speed up loading and Lighthouse scores too.

[Taishi]

Yeeees👍

[Anirudh Rowjee]

Perhaps the most to-the-point tailwind tutorial i've ever seen so far. Great Work!

[Taishi]

Thank you for the kind words 😆

[Fajar Siddiq]

maji yabai 🔥 thanks for sharing Taishi

[Taishi]

Hey, Fajar!

Thank you for the comment!
Maji Yabai🔥