How to use markdown and MDX in Next.js

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Markdown is a lightweight markup language used to format text. It allows you to write using plain text syntax and convert it to structurally valid HTML. It's commonly used for writing content on websites and blogs.

You write...

I **love** using [Next.js](https://nextjs.org/)

Output:

<p>I <strong>love</strong> using <a href="https://nextjs.org/">Next.js</a></p>

MDX is a superset of markdown that lets you write JSX directly in your markdown files. It is a powerful way to add dynamic interactivity and embed React components within your content.

Next.js can support both local MDX content inside your application, as well as remote MDX files fetched dynamically on the server. The Next.js plugin handles transforming markdown and React components into HTML, including support for usage in Server Components (the default in App Router).

Good to know: View the Portfolio Starter Kit template for a complete working example.

Install dependencies

The @next/mdx package, and related packages, are used to configure Next.js so it can process markdown and MDX. It sources data from local files, allowing you to create pages with a .md or .mdx extension, directly in your /pages or /app directory.

Install these packages to render MDX with Next.js:

pnpm add @next/mdx @mdx-js/loader @mdx-js/react @types/mdx

npm install @next/mdx @mdx-js/loader @mdx-js/react @types/mdx

yarn add @next/mdx @mdx-js/loader @mdx-js/react @types/mdx

bun add @next/mdx @mdx-js/loader @mdx-js/react @types/mdx

Configure `next.config.mjs`

Update the next.config.mjs file at your project's root to configure it to use MDX:

import createMDX from '@next/mdx'

/** @type {import('next').NextConfig} */
const nextConfig = {
  // Configure `pageExtensions` to include markdown and MDX files
  pageExtensions: ['js', 'jsx', 'md', 'mdx', 'ts', 'tsx'],
  // Optionally, add any other Next.js config below
}

const withMDX = createMDX({
  // Add markdown plugins here, as desired
})

// Merge MDX config with Next.js config
export default withMDX(nextConfig)

This allows .mdx files to act as pages, routes, or imports in your application.

Handling `.md` files

By default, next/mdx only compiles files with the .mdx extension. To handle .md files with webpack, update the extension option:

const withMDX = createMDX({
  extension: /\.(md|mdx)$/,
})

Add an `mdx-components.tsx` file

Create an mdx-components.tsx (or .js) file in the root of your project to define global MDX Components. For example, at the same level as pages or app, or inside src if applicable.

import type { MDXComponents } from 'mdx/types'

const components: MDXComponents = {}

export function useMDXComponents(): MDXComponents {
  return components
}

const components = {}

export function useMDXComponents() {
  return components
}

Good to know:

mdx-components.tsx is required to use @next/mdx with App Router and will not work without it.

Learn more about the mdx-components.tsx file convention.

Learn how to use custom styles and components.

Rendering MDX

You can render MDX using Next.js's file based routing or by importing MDX files into other pages.

Using file based routing

When using file based routing, you can use MDX pages like any other page.

In App Router apps, that includes being able to use metadata.

Create a new MDX page within the /app directory:

  my-project
  ├── app
  │   └── mdx-page
  │       └── page.(mdx/md)
  |── mdx-components.(tsx/js)
  └── package.json

Create a new MDX page within the /pages directory:

  my-project
  |── mdx-components.(tsx/js)
  ├── pages
  │   └── mdx-page.(mdx/md)
  └── package.json

You can use MDX in these files, and even import React components, directly inside your MDX page:

import { MyComponent } from 'my-component'

# Welcome to my MDX page!

This is some **bold** and _italics_ text.

This is a list in markdown:

- One
- Two
- Three

Checkout my React component:

<MyComponent />

Navigating to the /mdx-page route should display your rendered MDX page.

Using imports

Create a new page within the /app directory and an MDX file wherever you'd like:

  .
  ├── app/
  │   └── mdx-page/
  │       └── page.(tsx/js)
  ├── markdown/
  │   └── welcome.(mdx/md)
  ├── mdx-components.(tsx/js)
  └── package.json

Create a new page within the /pages directory and an MDX file wherever you'd like:

  .
  ├── markdown/
  │   └── welcome.(mdx/md)
  ├── pages/
  │   └── mdx-page.(tsx/js)
  ├── mdx-components.(tsx/js)
  └── package.json

You can use MDX in these files, and even import React components, directly inside your MDX page:

import { MyComponent } from 'my-component'

# Welcome to my MDX page!

This is some **bold** and _italics_ text.

This is a list in markdown:

- One
- Two
- Three

Checkout my React component:

<MyComponent />

Import the MDX file inside the page to display the content:

import Welcome from '@/markdown/welcome.mdx'

export default function Page() {
  return <Welcome />
}

import Welcome from '@/markdown/welcome.mdx'

export default function Page() {
  return <Welcome />
}

import Welcome from '@/markdown/welcome.mdx'

export default function Page() {
  return <Welcome />
}

import Welcome from '@/markdown/welcome.mdx'

export default function Page() {
  return <Welcome />
}

Navigating to the /mdx-page route should display your rendered MDX page.

Using dynamic imports

You can import dynamic MDX components instead of using filesystem routing for MDX files.

For example, you can have a dynamic route segment which loads MDX components from a separate directory:

generateStaticParams can be used to prerender the provided routes. By marking dynamicParams as false, accessing a route not defined in generateStaticParams will 404.

export default async function Page({
  params,
}: {
  params: Promise<{ slug: string }>
}) {
  const { slug } = await params
  const { default: Post } = await import(`@/content/${slug}.mdx`)

  return <Post />
}

export function generateStaticParams() {
  return [{ slug: 'welcome' }, { slug: 'about' }]
}

export const dynamicParams = false

export default async function Page({ params }) {
  const { slug } = await params
  const { default: Post } = await import(`@/content/${slug}.mdx`)

  return <Post />
}

export function generateStaticParams() {
  return [{ slug: 'welcome' }, { slug: 'about' }]
}

export const dynamicParams = false

Good to know: Ensure you specify the .mdx file extension in your import. While it is not required to use module path aliases (e.g., @/content), it does simplify your import path.

Using custom styles and components

Markdown, when rendered, maps to native HTML elements. For example, writing the following markdown:

## This is a heading

This is a list in markdown:

- One
- Two
- Three

Generates the following HTML:

<h2>This is a heading</h2>

<p>This is a list in markdown:</p>

<ul>
  <li>One</li>
  <li>Two</li>
  <li>Three</li>
</ul>

To style your markdown, you can provide custom components that map to the generated HTML elements. Styles and components can be implemented globally, locally, and with shared layouts.

Global styles and components

Adding styles and components in mdx-components.tsx will affect all MDX files in your application.

import type { MDXComponents } from 'mdx/types'
import Image, { ImageProps } from 'next/image'

// This file allows you to provide custom React components
// to be used in MDX files. You can import and use any
// React component you want, including inline styles,
// components from other libraries, and more.

const components = {
  // Allows customizing built-in components, e.g. to add styling.
  h1: ({ children }) => (
    <h1 style={{ color: 'red', fontSize: '48px' }}>{children}</h1>
  ),
  img: (props) => (
    <Image
      sizes="100vw"
      style={{ width: '100%', height: 'auto' }}
      {...(props as ImageProps)}
    />
  ),
} satisfies MDXComponents

export function useMDXComponents(): MDXComponents {
  return components
}

import Image from 'next/image'

// This file allows you to provide custom React components
// to be used in MDX files. You can import and use any
// React component you want, including inline styles,
// components from other libraries, and more.

const components = {
  // Allows customizing built-in components, e.g. to add styling.
  h1: ({ children }) => (
    <h1 style={{ color: 'red', fontSize: '48px' }}>{children}</h1>
  ),
  img: (props) => (
    <Image sizes="100vw" style={{ width: '100%', height: 'auto' }} {...props} />
  ),
}

export function useMDXComponents() {
  return components
}

Local styles and components

You can apply local styles and components to specific pages by passing them into imported MDX components. These will merge with and override global styles and components.

import Welcome from '@/markdown/welcome.mdx'

function CustomH1({ children }) {
  return <h1 style={{ color: 'blue', fontSize: '100px' }}>{children}</h1>
}

const overrideComponents = {
  h1: CustomH1,
}

export default function Page() {
  return <Welcome components={overrideComponents} />
}

import Welcome from '@/markdown/welcome.mdx'

function CustomH1({ children }) {
  return <h1 style={{ color: 'blue', fontSize: '100px' }}>{children}</h1>
}

const overrideComponents = {
  h1: CustomH1,
}

export default function Page() {
  return <Welcome components={overrideComponents} />
}

import Welcome from '@/markdown/welcome.mdx'

function CustomH1({ children }) {
  return <h1 style={{ color: 'blue', fontSize: '100px' }}>{children}</h1>
}

const overrideComponents = {
  h1: CustomH1,
}

export default function Page() {
  return <Welcome components={overrideComponents} />
}

import Welcome from '@/markdown/welcome.mdx'

function CustomH1({ children }) {
  return <h1 style={{ color: 'blue', fontSize: '100px' }}>{children}</h1>
}

const overrideComponents = {
  h1: CustomH1,
}

export default function Page() {
  return <Welcome components={overrideComponents} />
}

Shared layouts

To share a layout across MDX pages, you can use the built-in layouts support with the App Router.

export default function MdxLayout({ children }: { children: React.ReactNode }) {
  // Create any shared layout or styles here
  return <div style={{ color: 'blue' }}>{children}</div>
}

export default function MdxLayout({ children }) {
  // Create any shared layout or styles here
  return <div style={{ color: 'blue' }}>{children}</div>
}

To share a layout around MDX pages, create a layout component:

export default function MdxLayout({ children }: { children: React.ReactNode }) {
  // Create any shared layout or styles here
  return <div style={{ color: 'blue' }}>{children}</div>
}

export default function MdxLayout({ children }) {
  // Create any shared layout or styles here
  return <div style={{ color: 'blue' }}>{children}</div>
}

Then, import the layout component into the MDX page, wrap the MDX content in the layout, and export it:

import MdxLayout from '../components/mdx-layout'

# Welcome to my MDX page!

export default function MDXPage({ children }) {
  return <MdxLayout>{children}</MdxLayout>

}

Using Tailwind typography plugin

If you are using Tailwind to style your application, using the @tailwindcss/typography plugin will allow you to reuse your Tailwind configuration and styles in your markdown files.

The plugin adds a set of prose classes that can be used to add typographic styles to content blocks that come from sources, like markdown.

Install Tailwind typography and use with shared layouts to add the prose you want.

export default function MdxLayout({ children }: { children: React.ReactNode }) {
  // Create any shared layout or styles here
  return (
    <div className="prose prose-headings:mt-8 prose-headings:font-semibold prose-headings:text-black prose-h1:text-5xl prose-h2:text-4xl prose-h3:text-3xl prose-h4:text-2xl prose-h5:text-xl prose-h6:text-lg dark:prose-headings:text-white">
      {children}
    </div>
  )
}

export default function MdxLayout({ children }) {
  // Create any shared layout or styles here
  return (
    <div className="prose prose-headings:mt-8 prose-headings:font-semibold prose-headings:text-black prose-h1:text-5xl prose-h2:text-4xl prose-h3:text-3xl prose-h4:text-2xl prose-h5:text-xl prose-h6:text-lg dark:prose-headings:text-white">
      {children}
    </div>
  )
}

To share a layout around MDX pages, create a layout component:

export default function MdxLayout({ children }: { children: React.ReactNode }) {
  // Create any shared layout or styles here
  return (
    <div className="prose prose-headings:mt-8 prose-headings:font-semibold prose-headings:text-black prose-h1:text-5xl prose-h2:text-4xl prose-h3:text-3xl prose-h4:text-2xl prose-h5:text-xl prose-h6:text-lg dark:prose-headings:text-white">
      {children}
    </div>
  )
}

export default function MdxLayout({ children }) {
  // Create any shared layout or styles here
  return (
    <div className="prose prose-headings:mt-8 prose-headings:font-semibold prose-headings:text-black prose-h1:text-5xl prose-h2:text-4xl prose-h3:text-3xl prose-h4:text-2xl prose-h5:text-xl prose-h6:text-lg dark:prose-headings:text-white">
      {children}
    </div>
  )
}

Then, import the layout component into the MDX page, wrap the MDX content in the layout, and export it:

import MdxLayout from '../components/mdx-layout'

# Welcome to my MDX page!

export default function MDXPage({ children }) {
  return <MdxLayout>{children}</MdxLayout>

}

Frontmatter

Frontmatter is a YAML like key/value pairing that can be used to store data about a page. @next/mdx does not support frontmatter by default, though there are many solutions for adding frontmatter to your MDX content, such as:

@next/mdx does allow you to use exports like any other JavaScript component:

export const metadata = {
  author: 'John Doe',
}

# Blog post

Metadata can now be referenced outside of the MDX file:

import BlogPost, { metadata } from '@/content/blog-post.mdx'

export default function Page() {
  console.log('metadata: ', metadata)
  //=> { author: 'John Doe' }
  return <BlogPost />
}

import BlogPost, { metadata } from '@/content/blog-post.mdx'

export default function Page() {
  console.log('metadata: ', metadata)
  //=> { author: 'John Doe' }
  return <BlogPost />
}

import BlogPost, { metadata } from '@/content/blog-post.mdx'

export default function Page() {
  console.log('metadata: ', metadata)
  //=> { author: 'John Doe' }
  return <BlogPost />
}

import BlogPost, { metadata } from '@/content/blog-post.mdx'

export default function Page() {
  console.log('metadata: ', metadata)
  //=> { author: 'John Doe' }
  return <BlogPost />
}

A common use case for this is when you want to iterate over a collection of MDX and extract data. For example, creating a blog index page from all blog posts. You can use packages like Node's fs module or globby to read a directory of posts and extract the metadata.

Good to know:

Using fs, globby, etc. can only be used server-side.

View the Portfolio Starter Kit template for a complete working example.

remark and rehype Plugins

You can optionally provide remark and rehype plugins to transform the MDX content.

For example, you can use remark-gfm to support GitHub Flavored Markdown.

Since the remark and rehype ecosystem is ESM only, you'll need to use next.config.mjs or next.config.ts as the configuration file.

import remarkGfm from 'remark-gfm'
import createMDX from '@next/mdx'

/** @type {import('next').NextConfig} */
const nextConfig = {
  // Allow .mdx extensions for files
  pageExtensions: ['js', 'jsx', 'md', 'mdx', 'ts', 'tsx'],
  // Optionally, add any other Next.js config below
}

const withMDX = createMDX({
  // Add markdown plugins here, as desired
  options: {
    remarkPlugins: [remarkGfm],
    rehypePlugins: [],
  },
})

// Combine MDX and Next.js config
export default withMDX(nextConfig)

Using Plugins with Turbopack

To use plugins with Turbopack, upgrade to the latest @next/mdx and specify plugin names using a string:

import createMDX from '@next/mdx'

/** @type {import('next').NextConfig} */
const nextConfig = {
  pageExtensions: ['js', 'jsx', 'md', 'mdx', 'ts', 'tsx'],
}

const withMDX = createMDX({
  options: {
    remarkPlugins: [
      // Without options
      'remark-gfm',
      // With options
      ['remark-toc', { heading: 'The Table' }],
    ],
    rehypePlugins: [
      // Without options
      'rehype-slug',
      // With options
      ['rehype-katex', { strict: true, throwOnError: true }],
    ],
  },
})

export default withMDX(nextConfig)

Good to know:

remark and rehype plugins without serializable options cannot be used yet with Turbopack, because JavaScript functions can't be passed to Rust.

Deep Dive: How do you transform markdown into HTML?

React does not natively understand markdown. The markdown plaintext needs to first be transformed into HTML. This can be accomplished with remark and rehype.

remark is an ecosystem of tools around markdown. rehype is the same, but for HTML. For example, the following code snippet transforms markdown into HTML:

import { unified } from 'unified'
import remarkParse from 'remark-parse'
import remarkRehype from 'remark-rehype'
import rehypeSanitize from 'rehype-sanitize'
import rehypeStringify from 'rehype-stringify'

main()

async function main() {
  const file = await unified()
    .use(remarkParse) // Convert into markdown AST
    .use(remarkRehype) // Transform to HTML AST
    .use(rehypeSanitize) // Sanitize HTML input
    .use(rehypeStringify) // Convert AST into serialized HTML
    .process('Hello, Next.js!')

  console.log(String(file)) // <p>Hello, Next.js!</p>
}

The remark and rehype ecosystem contains plugins for syntax highlighting, linking headings, generating a table of contents, and more.

When using @next/mdx as shown above, you do not need to use remark or rehype directly, as it is handled for you. We're describing it here for a deeper understanding of what the @next/mdx package is doing underneath.

Using the Rust-based MDX compiler (experimental)

Next.js supports a new MDX compiler written in Rust. This compiler is still experimental and is not recommended for production use. To use the new compiler, you need to configure next.config.js when you pass it to withMDX:

module.exports = withMDX({
  experimental: {
    mdxRs: true,
  },
})

mdxRs also accepts an object to configure how to transform mdx files.

module.exports = withMDX({
  experimental: {
    mdxRs: {
      jsxRuntime?: string            // Custom jsx runtime
      jsxImportSource?: string       // Custom jsx import source,
      providerImportSource?: string  // Module providing a `useMDXComponents` context
      mdxType?: 'gfm' | 'commonmark' // Configure what kind of mdx syntax will be used to parse & transform
    },
  },
})

Helpful Links

Source: docs/01-app/02-guides/mdx.mdx