A guide for integrating Next.js with Expo for the web.
warning: Using Next.js is not an official part of Expo's universal app development workflow.
Next.js is a React framework that provides simple page-based routing as well as server-side rendering. To use Next.js with the Expo SDK, we recommend using @expo/next-adapter library to handle the configuration.
Using Expo with Next.js means you can share some of your existing components and APIs across your mobile and web app. Next.js has its own CLI that you'll need to use when developing for the web platform, so you'll need to start your web projects with the Next.js CLI and not with npx expo start.
Next.js can only be used with Expo for web as there is no support for Server-Side Rendering (SSR) for native apps.
To quickly get started, create a new project using with-nextjs template:
- npx create-expo-app -e with-nextjsnpx expo start — start the Expo projectnpx next dev — start the Next.js projectEnsure you have expo, next, @expo/next-adapter installed in your project:
- yarn add expo next @expo/next-adapterConfigure Next.js to transform language features:
Using Next.js with SWC is recommended. You can configure the babel.config.js to only account for native:
module.exports = function (api) {
api.cache(true);
return {
presets: ['babel-preset-expo'],
};
};
You will also have to force Next.js to use SWC by adding the following to your next.config.js:
module.exports = {
experimental: {
forceSwcTransforms: true,
},
};
Adjust your babel.config.js to conditionally add next/babel when bundling with webpack for web:
module.exports = function (api) {
// Detect web usage (this may change in the future if Next.js changes the loader)
const isWeb = api.caller(
caller =>
caller && (caller.name === 'babel-loader' || caller.name === 'next-babel-turbo-loader')
);
return {
presets: [
// Only use next in the browser, it'll break your native project
isWeb && require('next/babel'),
'babel-preset-expo',
].filter(Boolean),
};
};
Add the following to your next.config.js:
const { withExpo } = require('@expo/next-adapter');
module.exports = withExpo({
// transpilePackages is a Next.js +13.1 feature.
// older versions can use next-transpile-modules
transpilePackages: [
'react-native',
'expo',
// Add more React Native/Expo packages here...
],
});
The fully qualified Next.js config may look like:
const { withExpo } = require('@expo/next-adapter');
/** @type {import('next').NextConfig} */
const nextConfig = withExpo({
reactStrictMode: true,
swcMinify: true,
transpilePackages: [
'react-native',
'expo',
// Add more React Native/Expo packages here...
],
experimental: {
forceSwcTransforms: true,
},
});
module.exports = nextConfig;
The package react-native-web builds on the assumption of reset CSS styles. Here's how you reset styles in Next.js using the pages directory.
import { Children } from 'react';
import Document, { Html, Head, Main, NextScript } from 'next/document';
import { AppRegistry } from 'react-native';
// Follows the setup for react-native-web:
// https://necolas.github.io/react-native-web/docs/setup/#root-element
// Plus additional React Native scroll and text parity styles for various
// browsers.
// Force Next-generated DOM elements to fill their parent's height
const style = `
html, body, #__next {
-webkit-overflow-scrolling: touch;
}
#__next {
display: flex;
flex-direction: column;
height: 100%;
}
html {
scroll-behavior: smooth;
-webkit-text-size-adjust: 100%;
}
body {
/* Allows you to scroll below the viewport; default value is visible */
overflow-y: auto;
overscroll-behavior-y: none;
text-rendering: optimizeLegibility;
-webkit-font-smoothing: antialiased;
-moz-osx-font-smoothing: grayscale;
-ms-overflow-style: scrollbar;
}
`;
export default class MyDocument extends Document {
static async getInitialProps({ renderPage }) {
AppRegistry.registerComponent('main', () => Main);
const { getStyleElement } = AppRegistry.getApplication('main');
const page = await renderPage();
const styles = [
<style key="react-native-style" dangerouslySetInnerHTML={{ __html: style }} />,
getStyleElement(),
];
return { ...page, styles: Children.toArray(styles) };
}
render() {
return (
<Html style={{ height: '100%' }}>
<Head />
<body style={{ height: '100%', overflow: 'hidden' }}>
<Main />
<NextScript />
</body>
</Html>
);
}
}
import Head from 'next/head';
export default function App({ Component, pageProps }) {
return (
<>
<Head>
<meta name="viewport" content="width=device-width, initial-scale=1" />
</Head>
<Component {...pageProps} />
</>
);
}
By default, modules in the React Native ecosystem are not transpiled to run in web browsers. React Native relies on advanced caching in Metro to reload quickly. Next.js uses webpack, which does not have the same level of caching, so no node modules are transpiled by default. You will have to manually mark every module you want to transpile with the transpilePackages option in next.config.js:
const { withExpo } = require('@expo/next-adapter');
module.exports = withExpo({
experimental: {
transpilePackages: [
// NOTE: Even though `react-native` is never used in Next.js,
// you need to list `react-native` because `react-native-web`
// is aliased to `react-native`. Adding `react-native-web` will not work.
'react-native',
'expo',
// Add more React Native/Expo packages here...
],
},
});
This is Vercel's preferred method for deploying Next.js projects to production.
Add a build script to your package.json
{
"scripts": {
"build": "next build"
}
}
Install the Vercel CLI:
- npm i -g vercelDeploy to Vercel:
- vercelUsing Next.js for the web means you will be bundling with the Next.js webpack config. This will lead to some core differences in how you develop your app vs your website.
If you would like to help make Next.js support in Expo better, feel free to open a PR or submit an issue:
Figure out which module has the import statement and add it to the transpilePackages option in next.config.js:
const { withExpo } = require('@expo/next-adapter');
module.exports = withExpo({
experimental: {
transpilePackages: [
'react-native',
'expo',
// Add the failing package here, and restart the server...
],
},
});