Set up Master CSS in Next.js

Guide to setting up Master CSS in your Next.js project.

Master CSS Runtime Rendering observes changes in DOM class names at browser runtime, generates corresponding CSS rules, and injects them into the running style sheet.

Fixed style cost

All features work out of the box with ~16KB transfer cost

Fully automatic

Capture any program-generated class names

CSS lifecycle

CSS is generated on demand and frees memory when not in use

Quick start

Clone the example

Copy-paste the following commands to quickly start using the

You can skip all installation steps.

npx degit master-co/css/examples/next.js-with-runtime-rendering my-project
cd my-project
npm install @master/css.react@beta
npm install
npm run dev


Create a Next.js project

If you don't have a Next.js project, create one first. It's recommended to refer to Create Next App.

npx create-next-app@latest --experimental-app --ts
cd project

Install Master CSS

Install Master CSS React into your project via package managers.

npm install @master/css.react@beta

Initialize configuration file

Run npx mcss init to create a configuration file master.css.ts.

npx mcss init

Set up CSS runtime engine

Register Master CSS with official CSSProvider and provide instance context.

  1. Register the CSSProvider
  2. Import the config ../master.css
  3. Add display: 'none' in <html> to avoid FOUC
import './globals.css'
import { CSSProvider } from '@master/css.react'
import config from '../master.css'
export const metadata = {
title: 'Create Next App',
description: 'Generated by create next app',
export default function RootLayout({ children }: { children: React.ReactNode }) {
return (
<html lang="en" style={{ display: 'none' }}>
<CSSProvider config={config}>

Launch server

Run npm run dev to start your Next.js development server

npm run dev

Start using Master CSS

Now style your first element using Master CSS syntax!

export default function Home() {
return (
<h1 className="font:40 font:heavy italic m:50 text:center">Hello World</h1>

Open your browser to watch the changes.


Hello World

MIT License © Aoyue Design LLC.