content: [API Reference](https://react.dev/reference/react)
  
  [Static APIs](https://react.dev/reference/react-dom/static)
  
  # prerender[Link for this heading]()
  
  `prerender` renders a React tree to a static HTML string using a [Web Stream](https://developer.mozilla.org/en-US/docs/Web/API/Streams_API).
  
  ```
  
  const {prelude} = await prerender(reactNode, options?)
  ```
  
  - [Reference]()
    
    - [`prerender(reactNode, options?)`]()
  - [Usage]()
    
    - [Rendering a React tree to a stream of static HTML]()
    - [Rendering a React tree to a string of static HTML]()
    - [Waiting for all data to load]()
  - [Troubleshooting]()
    
    - [My stream doesn’t start until the entire app is rendered]()
  
  ### Note
  
  This API depends on [Web Streams.](https://developer.mozilla.org/en-US/docs/Web/API/Streams_API) For Node.js, use [`prerenderToNodeStream`](https://react.dev/reference/react-dom/static/prerenderToNodeStream) instead.
  
  * * *
  
  ## Reference[Link for Reference]()
  
  ### `prerender(reactNode, options?)`[Link for this heading]()
  
  Call `prerender` to render your app to static HTML.
  
  ```
  
  import { prerender } from 'react-dom/static';
  
  
  
  async function handler(request) {
  
    const {prelude} = await prerender(<App />, {
  
      bootstrapScripts: ['/main.js']
  
    });
  
    return new Response(prelude, {
  
      headers: { 'content-type': 'text/html' },
  
    });
  
  }
  ```
  
  On the client, call [`hydrateRoot`](https://react.dev/reference/react-dom/client/hydrateRoot) to make the server-generated HTML interactive.
  
  [See more examples below.]()
  
  #### Parameters[Link for Parameters]()
  
  - `reactNode`: A React node you want to render to HTML. For example, a JSX node like `<App />`. It is expected to represent the entire document, so the App component should render the `<html>` tag.
  - **optional** `options`: An object with static generation options.
    
    - **optional** `bootstrapScriptContent`: If specified, this string will be placed in an inline `<script>` tag.
    - **optional** `bootstrapScripts`: An array of string URLs for the `<script>` tags to emit on the page. Use this to include the `<script>` that calls [`hydrateRoot`.](https://react.dev/reference/react-dom/client/hydrateRoot) Omit it if you don’t want to run React on the client at all.
    - **optional** `bootstrapModules`: Like `bootstrapScripts`, but emits [`<script type="module">`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules) instead.
    - **optional** `identifierPrefix`: A string prefix React uses for IDs generated by [`useId`.](https://react.dev/reference/react/useId) Useful to avoid conflicts when using multiple roots on the same page. Must be the same prefix as passed to [`hydrateRoot`.](https://react.dev/reference/react-dom/client/hydrateRoot)
    - **optional** `namespaceURI`: A string with the root [namespace URI](https://developer.mozilla.org/en-US/docs/Web/API/Document/createElementNS) for the stream. Defaults to regular HTML. Pass `'http://www.w3.org/2000/svg'` for SVG or `'http://www.w3.org/1998/Math/MathML'` for MathML.
    - **optional** `onError`: A callback that fires whenever there is a server error, whether [recoverable]() or [not.]() By default, this only calls `console.error`. If you override it to [log crash reports,]() make sure that you still call `console.error`. You can also use it to [adjust the status code]() before the shell is emitted.
    - **optional** `progressiveChunkSize`: The number of bytes in a chunk. [Read more about the default heuristic.](https://github.com/facebook/react/blob/14c2be8dac2d5482fda8a0906a31d239df8551fc/packages/react-server/src/ReactFizzServer.js)
    - **optional** `signal`: An [abort signal](https://developer.mozilla.org/en-US/docs/Web/API/AbortSignal) that lets you [abort server rendering]() and render the rest on the client.
  
  #### Returns[Link for Returns]()
  
  `prerender` returns a Promise:
  
  - If rendering the is successful, the Promise will resolve to an object containing:
    
    - `prelude`: a [Web Stream](https://developer.mozilla.org/en-US/docs/Web/API/Streams_API) of HTML. You can use this stream to send a response in chunks, or you can read the entire stream into a string.
  - If rendering fails, the Promise will be rejected. [Use this to output a fallback shell.]()
  
  ### Note
  
  ### When should I use `prerender`?[Link for this heading]()
  
  The static `prerender` API is used for static server-side generation (SSG). Unlike `renderToString`, `prerender` waits for all data to load before resolving. This makes it suitable for generating static HTML for a full page, including data that needs to be fetched using Suspense. To stream content as it loads, use a streaming server-side render (SSR) API like [renderToReadableStream](https://react.dev/reference/react-dom/server/renderToReadableStream).
  
  * * *
  
  ## Usage[Link for Usage]()
  
  ### Rendering a React tree to a stream of static HTML[Link for Rendering a React tree to a stream of static HTML]()
  
  Call `prerender` to render your React tree to static HTML into a [Readable Web Stream:](https://developer.mozilla.org/en-US/docs/Web/API/ReadableStream):
  
  ```
  
  import { prerender } from 'react-dom/static';
  
  
  
  async function handler(request) {
  
    const {prelude} = await prerender(<App />, {
  
      bootstrapScripts: ['/main.js']
  
    });
  
    return new Response(prelude, {
  
      headers: { 'content-type': 'text/html' },
  
    });
  
  }
  ```
  
  Along with the root component, you need to provide a list of bootstrap `<script>` paths. Your root component should return **the entire document including the root `<html>` tag.**
  
  For example, it might look like this:
  
  ```
  
  export default function App() {
  
    return (
  
      <html>
  
        <head>
  
          <meta charSet="utf-8" />
  
          <meta name="viewport" content="width=device-width, initial-scale=1" />
  
          <link rel="stylesheet" href="/styles.css"></link>
  
          <title>My app</title>
  
        </head>
  
        <body>
  
          <Router />
  
        </body>
  
      </html>
  
    );
  
  }
  ```
  
  React will inject the [doctype](https://developer.mozilla.org/en-US/docs/Glossary/Doctype) and your bootstrap `<script>` tags into the resulting HTML stream:
  
  ```
  
  <!DOCTYPE html>
  
  <html>
  
    <!-- ... HTML from your components ... -->
  
  </html>
  
  <script src="/main.js" async=""></script>
  ```
  
  On the client, your bootstrap script should [hydrate the entire `document` with a call to `hydrateRoot`:](https://react.dev/reference/react-dom/client/hydrateRoot)
  
  ```
  
  import { hydrateRoot } from 'react-dom/client';
  
  import App from './App.js';
  
  
  
  hydrateRoot(document, <App />);
  ```
  
  This will attach event listeners to the static server-generated HTML and make it interactive.
  
  ##### Deep Dive
  
  #### Reading CSS and JS asset paths from the build output[Link for Reading CSS and JS asset paths from the build output]()
  
  Show Details
  
  The final asset URLs (like JavaScript and CSS files) are often hashed after the build. For example, instead of `styles.css` you might end up with `styles.123456.css`. Hashing static asset filenames guarantees that every distinct build of the same asset will have a different filename. This is useful because it lets you safely enable long-term caching for static assets: a file with a certain name would never change content.
  
  However, if you don’t know the asset URLs until after the build, there’s no way for you to put them in the source code. For example, hardcoding `"/styles.css"` into JSX like earlier wouldn’t work. To keep them out of your source code, your root component can read the real filenames from a map passed as a prop:
  
  ```
  
  export default function App({ assetMap }) {
  
    return (
  
      <html>
  
        <head>
  
          <title>My app</title>
  
          <link rel="stylesheet" href={assetMap['styles.css']}></link>
  
        </head>
  
        ...
  
      </html>
  
    );
  
  }
  ```
  
  On the server, render `<App assetMap={assetMap} />` and pass your `assetMap` with the asset URLs:
  
  ```
  
  // You'd need to get this JSON from your build tooling, e.g. read it from the build output.
  
  const assetMap = {
  
    'styles.css': '/styles.123456.css',
  
    'main.js': '/main.123456.js'
  
  };
  
  
  
  async function handler(request) {
  
    const {prelude} = await prerender(<App assetMap={assetMap} />, {
  
      bootstrapScripts: [assetMap['/main.js']]
  
    });
  
    return new Response(prelude, {
  
      headers: { 'content-type': 'text/html' },
  
    });
  
  }
  ```
  
  Since your server is now rendering `<App assetMap={assetMap} />`, you need to render it with `assetMap` on the client too to avoid hydration errors. You can serialize and pass `assetMap` to the client like this:
  
  ```
  
  // You'd need to get this JSON from your build tooling.
  
  const assetMap = {
  
    'styles.css': '/styles.123456.css',
  
    'main.js': '/main.123456.js'
  
  };
  
  
  
  async function handler(request) {
  
    const {prelude} = await prerender(<App assetMap={assetMap} />, {
  
      // Careful: It's safe to stringify() this because this data isn't user-generated.
  
      bootstrapScriptContent: `window.assetMap = ${JSON.stringify(assetMap)};`,
  
      bootstrapScripts: [assetMap['/main.js']],
  
    });
  
    return new Response(prelude, {
  
      headers: { 'content-type': 'text/html' },
  
    });
  
  }
  ```
  
  In the example above, the `bootstrapScriptContent` option adds an extra inline `<script>` tag that sets the global `window.assetMap` variable on the client. This lets the client code read the same `assetMap`:
  
  ```
  
  import { hydrateRoot } from 'react-dom/client';
  
  import App from './App.js';
  
  
  
  hydrateRoot(document, <App assetMap={window.assetMap} />);
  ```
  
  Both client and server render `App` with the same `assetMap` prop, so there are no hydration errors.
  
  * * *
  
  ### Rendering a React tree to a string of static HTML[Link for Rendering a React tree to a string of static HTML]()
  
  Call `prerender` to render your app to a static HTML string:
  
  ```
  
  import { prerender } from 'react-dom/static';
  
  
  
  async function renderToString() {
  
    const {prelude} = await prerender(<App />, {
  
      bootstrapScripts: ['/main.js']
  
    });
  
    
  
    const reader = stream.getReader();
  
    let content = '';
  
    while (true) {
  
      const {done, value} = await reader.read();
  
      if (done) {
  
        return content;
  
      }
  
      content += Buffer.from(value).toString('utf8');
  
    }
  
  }
  ```
  
  This will produce the initial non-interactive HTML output of your React components. On the client, you will need to call [`hydrateRoot`](https://react.dev/reference/react-dom/client/hydrateRoot) to *hydrate* that server-generated HTML and make it interactive.
  
  * * *
  
  ### Waiting for all data to load[Link for Waiting for all data to load]()
  
  `prerender` waits for all data to load before finishing the static HTML generation and resolving. For example, consider a profile page that shows a cover, a sidebar with friends and photos, and a list of posts:
  
  ```
  
  function ProfilePage() {
  
    return (
  
      <ProfileLayout>
  
        <ProfileCover />
  
        <Sidebar>
  
          <Friends />
  
          <Photos />
  
        </Sidebar>
  
        <Suspense fallback={<PostsGlimmer />}>
  
          <Posts />
  
        </Suspense>
  
      </ProfileLayout>
  
    );
  
  }
  ```
  
  Imagine that `<Posts />` needs to load some data, which takes some time. Ideally, you’d want wait for the posts to finish so it’s included in the HTML. To do this, you can use Suspense to suspend on the data, and `prerender` will wait for the suspended content to finish before resolving to the static HTML.
  
  ### Note
  
  **Only Suspense-enabled data sources will activate the Suspense component.** They include:
  
  - Data fetching with Suspense-enabled frameworks like [Relay](https://relay.dev/docs/guided-tour/rendering/loading-states/) and [Next.js](https://nextjs.org/docs/getting-started/react-essentials)
  - Lazy-loading component code with [`lazy`](https://react.dev/reference/react/lazy)
  - Reading the value of a Promise with [`use`](https://react.dev/reference/react/use)
  
  Suspense **does not** detect when data is fetched inside an Effect or event handler.
  
  The exact way you would load data in the `Posts` component above depends on your framework. If you use a Suspense-enabled framework, you’ll find the details in its data fetching documentation.
  
  Suspense-enabled data fetching without the use of an opinionated framework is not yet supported. The requirements for implementing a Suspense-enabled data source are unstable and undocumented. An official API for integrating data sources with Suspense will be released in a future version of React.
  
  * * *
  
  ## Troubleshooting[Link for Troubleshooting]()
  
  ### My stream doesn’t start until the entire app is rendered[Link for My stream doesn’t start until the entire app is rendered]()
  
  The `prerender` response waits for the entire app to finish rendering, including waiting for all suspense boundaries to resolve, before resolving. It is designed for static site generation (SSG) ahead of time and does not support streaming more content as it loads.
  
  To stream content as it loads, use a streaming server render API like [renderToReadableStream](https://react.dev/reference/react-dom/server/renderToReadableStream).
  
  [PreviousStatic APIs](https://react.dev/reference/react-dom/static)
  
  [NextprerenderToNodeStream](https://react.dev/reference/react-dom/static/prerenderToNodeStream)