docs/01-app/03-api-reference/04-functions/catchError.mdx
The unstable_catchError function creates a component that wraps its children in an error boundary. It provides a programmatic alternative to the error.js file convention, enabling component-level error recovery anywhere in your component tree.
Compared to a custom React error boundary, unstable_catchError is designed to work with Next.js out of the box:
unstable_retry() re-fetches and re-renders the error boundary's children, including Server Components.redirect() and notFound() work by throwing special errors under the hood. unstable_catchError handles these seamlessly, so they're not accidentally caught by your error boundary.unstable_catchError can be called from Client Components.
'use client'
import { unstable_catchError, type ErrorInfo } from 'next/error'
function ErrorFallback(
props: { title: string },
{ error, unstable_retry }: ErrorInfo
) {
return (
<div>
<h2>{props.title}</h2>
<p>{error.message}</p>
<button onClick={() => unstable_retry()}>Try again</button>
</div>
)
}
export default unstable_catchError(ErrorFallback)
'use client'
import { unstable_catchError } from 'next/error'
function ErrorFallback(props, { error, unstable_retry }) {
return (
<div>
<h2>{props.title}</h2>
<p>{error.message}</p>
<button onClick={() => unstable_retry()}>Try again</button>
</div>
)
}
export default unstable_catchError(ErrorFallback)
unstable_catchError accepts a single argument:
const ErrorWrapper = unstable_catchError(fallback)
fallbackA function that renders the error UI when an error is caught. It receives two arguments:
props — The props passed to the wrapper component (excluding children).errorInfo — An object containing information about the error:| Property | Type | Description |
|---|---|---|
error | Error | The error instance that was caught. |
unstable_retry | () => void | Re-fetches and re-renders the error boundary's children. If successful, the fallback is replaced with the re-rendered result. |
reset | () => void | Resets the error state and re-renders without re-fetching. Use unstable_retry() in most cases. |
The fallback function must be a Client Component (or defined in a 'use client' module).
unstable_catchError returns a React component that:
children.children in an error boundary.fallback when an error is caught in children.Define a fallback and use the returned component to wrap parts of your UI:
import ErrorWrapper from '../custom-error-boundary'
export default function Component({ children }: { children: React.ReactNode }) {
return <ErrorWrapper title="Dashboard Error">{children}</ErrorWrapper>
}
import ErrorWrapper from '../custom-error-boundary'
export default function Component({ children }) {
return <ErrorWrapper title="Dashboard Error">{children}</ErrorWrapper>
}
Use unstable_retry() to prompt the user to recover from the error. When called, the function re-fetches and re-renders the error boundary's children. If successful, the fallback is replaced with the re-rendered result.
In most cases, use unstable_retry() instead of reset(). The reset() function only clears the error state and re-renders without re-fetching, which means it won't recover from Server Component errors.
'use client'
import { unstable_catchError, type ErrorInfo } from 'next/error'
function ErrorFallback(props: {}, { error, unstable_retry, reset }: ErrorInfo) {
return (
<div>
<p>{error.message}</p>
<button onClick={() => unstable_retry()}>Try again</button>
<button onClick={() => reset()}>Reset</button>
</div>
)
}
export default unstable_catchError(ErrorFallback)
'use client'
import { unstable_catchError } from 'next/error'
function ErrorFallback(props, { error, unstable_retry, reset }) {
return (
<div>
<p>{error.message}</p>
<button onClick={() => unstable_retry()}>Try again</button>
<button onClick={() => reset()}>Reset</button>
</div>
)
}
export default unstable_catchError(ErrorFallback)
You can pass server-rendered content as a prop to display data-driven fallback UI. This works by rendering a Server Component as a React.ReactNode prop that the fallback displays when an error is caught.
Good to know: This pattern eagerly renders the fallback on every page render, even when no error occurs. For most use cases, a simpler client-side fallback is sufficient.
'use client'
import { unstable_catchError, type ErrorInfo } from 'next/error'
function ErrorFallback(
props: { fallback: React.ReactNode },
errorInfo: ErrorInfo
) {
return props.fallback
}
export default unstable_catchError(ErrorFallback)
'use client'
import { unstable_catchError } from 'next/error'
function ErrorFallback(props, errorInfo) {
return props.fallback
}
export default unstable_catchError(ErrorFallback)
import ErrorBoundary from '../error-boundary'
async function ErrorFallback() {
const data = await getData()
return <div>{data.message}</div>
}
export default function Component({ children }: { children: React.ReactNode }) {
return <ErrorBoundary fallback={<ErrorFallback />}>{children}</ErrorBoundary>
}
import ErrorBoundary from '../error-boundary'
async function ErrorFallback() {
const data = await getData()
return <div>{data.message}</div>
}
export default function Component({ children }) {
return <ErrorBoundary fallback={<ErrorFallback />}>{children}</ErrorBoundary>
}
Good to know:
- Unlike the
error.jsfile convention which is scoped to route segments,unstable_catchErrorcan be used to wrap any part of your component tree for component-level error recovery.- Props passed to the wrapper component are forwarded to the fallback function, making it easy to create reusable error UIs with different configurations.
- You don't need to wrap
error.jsdefault exports withunstable_catchError. Theerror.jsfile convention already renders inside a built-in error boundary provided by Next.js.
| Version | Changes |
|---|---|
v16.2.0 | unstable_catchError introduced. |