Caching and Revalidating (Previous Model)

Caching fetch requests

By default, fetch requests are not cached. You can cache individual requests by setting the cache option to 'force-cache'.

export default async function Page() {
  const data = await fetch('https://...', { cache: 'force-cache' })
}

See the fetch API reference to learn more.

unstable_cache for non-fetch functions

unstable_cache allows you to cache the result of database queries and other async functions that don't use fetch. Wrap unstable_cache around the function:

import { unstable_cache } from 'next/cache'
import { db } from '@/lib/db'
 
export const getCachedUser = unstable_cache(
  async (id: string) => {
    return db
      .select()
      .from(users)
      .where(eq(users.id, id))
      .then((res) => res[0])
  },
  ['user'], // cache key prefix
  {
    tags: ['user'],
    revalidate: 3600,
  }
)

The third argument accepts:

• tags: an array of tags for on-demand revalidation with revalidateTag.
• revalidate: the number of seconds before the cache is revalidated.

See the unstable_cache API reference to learn more.

Route segment config

You can configure caching behavior at the route level by exporting config options from a Page, Layout, or Route Handler.

dynamic

Change the dynamic behavior of a layout or page to fully static or fully dynamic.

export const dynamic = 'auto'
// 'auto' | 'force-dynamic' | 'error' | 'force-static'

• 'auto' (default): The default option to cache as much as possible without preventing any components from opting into dynamic behavior.
• 'force-dynamic': Force dynamic rendering, which will result in routes being rendered for each user at request time. This option is equivalent to:
  • Setting the option of every fetch() request in a layout or page to { cache: 'no-store', next: { revalidate: 0 } }.
  • Setting the segment config to export const fetchCache = 'force-no-store'
• 'error': Force prerendering and cache the data of a layout or page by causing an error if any components use Request-time APIs or uncached data. This option is equivalent to:
  • getStaticProps() in the pages directory.
  • Setting the option of every fetch() request in a layout or page to { cache: 'force-cache' }.
  • Setting the segment config to fetchCache = 'only-cache'.
• 'force-static': Force prerendering and cache the data of a layout or page by forcing cookies, headers() and useSearchParams() to return empty values. It is possible to revalidate, revalidatePath, or revalidateTag, in pages or layouts rendered with force-static.

fetchCache

export const fetchCache = 'auto'
// 'auto' | 'default-cache' | 'only-cache'
// 'force-cache' | 'force-no-store' | 'default-no-store' | 'only-no-store'

Time-based revalidation

Use the next.revalidate option on fetch to revalidate data after a specified number of seconds:

export default async function Page() {
  const data = await fetch('https://...', { next: { revalidate: 3600 } })
}

For non-fetch functions, unstable_cache accepts a revalidate option in its configuration (see example above).

Route segment config revalidate

Set the default revalidation time for a layout or page. This option does not override the revalidate value set by individual fetch requests.

export const revalidate = false
// false | 0 | number

• false (default): The default heuristic to cache any fetch requests that set their cache option to 'force-cache' or are discovered before a Request-time API is used. Semantically equivalent to revalidate: Infinity which effectively means the resource should be cached indefinitely. It is still possible for individual fetch requests to use cache: 'no-store' or revalidate: 0 to avoid being cached and make the route dynamically rendered. Or set revalidate to a positive number lower than the route default to increase the revalidation frequency of a route.
• 0: Ensure a layout or page is always dynamically rendered even if no Request-time APIs or uncached data fetches are discovered. This option changes the default of fetch requests that do not set a cache option to 'no-store' but leaves fetch requests that opt into 'force-cache' or use a positive revalidate as is.
• number: (in seconds) Set the default revalidation frequency of a layout or page to n seconds.

Revalidation frequency

• The lowest revalidate across each layout and page of a single route will determine the revalidation frequency of the entire route. This ensures that child pages are revalidated as frequently as their parent layouts.
• Individual fetch requests can set a lower revalidate than the route's default revalidate to increase the revalidation frequency of the entire route. This allows you to dynamically opt-in to more frequent revalidation for certain routes based on some criteria.

On-demand revalidation

To revalidate cached data after an event, use revalidateTag or revalidatePath in a Server Action or Route Handler.

Tagging cached data

Tag fetch requests with next.tags to enable on-demand cache invalidation:

export async function getUserById(id: string) {
  const data = await fetch(`https://...`, {
    next: { tags: ['user'] },
  })
}

For non-fetch functions, unstable_cache also accepts a tags option (see example above).

revalidateTag

Invalidate cached data by tag using revalidateTag:

import { revalidateTag } from 'next/cache'
 
export async function updateUser(id: string) {
  // Mutate data
  revalidateTag('user')
}

revalidatePath

Invalidate all cached data for a specific route path using revalidatePath:

import { revalidatePath } from 'next/cache'
 
export async function updateUser(id: string) {
  // Mutate data
  revalidatePath('/profile')
}

Deduplicating requests

If you are not using fetch (which is automatically memoized), and instead using an ORM or database directly, you can wrap your data access with the React cache function to deduplicate requests within a single render pass:

import { cache } from 'react'
import { db, posts, eq } from '@/lib/db'
 
export const getPost = cache(async (id: string) => {
  const post = await db.query.posts.findFirst({
    where: eq(posts.id, parseInt(id)),
  })
})

Preloading data

You can preload data by creating a utility function that you eagerly call above blocking requests. This lets you initiate data fetching early, so the data is already available by the time the component renders.

Combine the server-only package with React's cache to create a reusable preload utility:

import { cache } from 'react'
import 'server-only'
 
export const getItem = cache(async (id: string) => {
  // ...
})
 
export const preload = (id: string) => {
  void getItem(id)
}

Then call preload() before any blocking work so the data starts loading immediately:

import { getItem, preload, checkIsAvailable } from '@/lib/data'
 
export default async function Page({
  params,
}: {
  params: Promise<{ id: string }>
}) {
  const { id } = await params
  // Start loading item data
  preload(id)
  // Perform another asynchronous task
  const isAvailable = await checkIsAvailable()
 
  return isAvailable ? <Item id={id} /> : null
}
 
async function Item({ id }: { id: string }) {
  const result = await getItem(id)
  // ...
}