React DOM APIs

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APIs

These APIs can be imported from your components. They are rarely used:

• createPortal lets you render child components in a different part of the DOM tree.
• flushSync lets you force React to flush a state update and update the DOM synchronously.

Resource Preloading APIs

These APIs can be used to make apps faster by pre-loading resources such as scripts, stylesheets, and fonts as soon as you know you need them, for example before navigating to another page where the resources will be used.

React-based frameworks frequently handle resource loading for you, so you might not have to call these APIs yourself. Consult your framework’s documentation for details.

• prefetchDNS lets you prefetch the IP address of a DNS domain name that you expect to connect to.
• preconnect lets you connect to a server you expect to request resources from, even if you don’t know what resources you’ll need yet.
• preload lets you fetch a stylesheet, font, image, or external script that you expect to use.
• preloadModule lets you fetch an ESM module that you expect to use.
• preinit lets you fetch and evaluate an external script or fetch and insert a stylesheet.
• preinitModule lets you fetch and evaluate an ESM module.

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Entry points

The react-dom package provides two additional entry points:

• react-dom/client contains APIs to render React components on the client (in the browser).
• react-dom/server contains APIs to render React components on the server.

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Deprecated APIs

• findDOMNode finds the closest DOM node corresponding to a class component instance.
• hydrate mounts a tree into the DOM created from server HTML. Deprecated in favor of hydrateRoot.
• render mounts a tree into the DOM. Deprecated in favor of createRoot.
• unmountComponentAtNode unmounts a tree from the DOM. Deprecated in favor of root.unmount().