wilddragon-site/node_modules/next/dist/docs/01-app/03-api-reference/04-functions/not-found.md

title	description
notFound	API Reference for the notFound function.

The notFound function allows you to render the not-found file within a route segment as well as inject a <meta name="robots" content="noindex" /> tag for search engines.

notFound()

Invoking the notFound() function throws a NEXT_HTTP_ERROR_FALLBACK;404 error and terminates rendering of the route segment in which it was thrown. Specifying a not-found file allows you to gracefully handle such errors by rendering a Not Found UI within the segment.

import { notFound } from 'next/navigation'

async function fetchUser(id) {
  const res = await fetch('https://...')
  if (!res.ok) return undefined
  return res.json()
}

export default async function Profile({ params }) {
  const { id } = await params
  const user = await fetchUser(id)

  if (!user) {
    notFound()
  }

  // ...
}

Good to know: notFound() does not require you to use return notFound() due to using the TypeScript never type.

Version History

Version	Changes
v13.0.0	notFound introduced.