--- title: Error Handling description: Handle runtime errors by automatically wrapping route segments and their nested children in a React Error Boundary. --- The `error.js` file convention allows you to gracefully handle runtime errors in [nested routes](/docs/app/building-your-application/routing#nested-routes). - Automatically wrap a route segment and its nested children in a [React Error Boundary](https://react.dev/reference/react/Component#catching-rendering-errors-with-an-error-boundary). - Create error UI tailored to specific segments using the file-system hierarchy to adjust granularity. - Isolate errors to affected segments while keeping the rest of the app functional. - Add functionality to attempt to recover from an error without a full page reload. Create error UI by adding an `error.js` file inside a route segment and exporting a React component: error.js special file ```tsx filename="app/dashboard/error.tsx" switcher 'use client' // Error components must be Client Components import { useEffect } from 'react' export default function Error({ error, reset, }: { error: Error reset: () => void }) { useEffect(() => { // Log the error to an error reporting service console.error(error) }, [error]) return (

Something went wrong!

) } ``` ```jsx filename="app/dashboard/error.js" switcher 'use client' // Error components must be Client Components import { useEffect } from 'react' export default function Error({ error, reset }) { useEffect(() => { // Log the error to an error reporting service console.error(error) }, [error]) return (

Something went wrong!

) } ``` ### How `error.js` Works How error.js works - `error.js` automatically creates an [React Error Boundary](https://react.dev/reference/react/Component#catching-rendering-errors-with-an-error-boundary) that **wraps** a nested child segment or `page.js` component. - The React component exported from the `error.js` file is used as the **fallback** component. - If an error is thrown within the error boundary, the error is **contained**, and the fallback component is **rendered**. - When the fallback error component is active, layouts **above** the error boundary **maintain** their state and **remain** interactive, and the error component can display functionality to recover from the error. ### Recovering From Errors The cause of an error can sometimes be temporary. In these cases, simply trying again might resolve the issue. An error component can use the `reset()` function to prompt the user to attempt to recover from the error. When executed, the function will try to re-render the Error boundary's contents. If successful, the fallback error component is replaced with the result of the re-render. ```tsx filename="app/dashboard/error.tsx" switcher 'use client' export default function Error({ error, reset, }: { error: Error reset: () => void }) { return (

Something went wrong!

) } ``` ```jsx filename="app/dashboard/error.js" switcher 'use client' export default function Error({ error, reset }) { return (

Something went wrong!

) } ``` ### Nested Routes React components created through [special files](/docs/app/building-your-application/routing#file-conventions) are rendered in a [specific nested hierarchy](/docs/app/building-your-application/routing#component-hierarchy). For example, a nested route with two segments that both include `layout.js` and `error.js` files are rendered in the following _simplified_ component hierarchy: Nested Error Component Hierarchy The nested component hierarchy has implications for the behavior of `error.js` files across a nested route: - Errors bubble up to the nearest parent error boundary. This means an `error.js` file will handle errors for all its nested child segments. More or less granular error UI can be achieved by placing `error.js` files at different levels in the nested folders of a route. - An `error.js` boundary will **not** handle errors thrown in a `layout.js` component in the **same** segment because the error boundary is nested **inside** that layouts component. ### Handling Errors in Layouts `error.js` boundaries do **not** catch errors thrown in `layout.js` or `template.js` components of the same segment. This [intentional hierarchy](#nested-routes) keeps important UI that is shared between sibling routes (such as navigation) visible and functional when an error occurs. To handle errors within a specific layout or template, place an `error.js` file in the layouts parent segment. To handle errors within the root layout or template, use a variation of `error.js` called `global-error.js`. ### Handling Errors in Root Layouts The root `app/error.js` boundary does **not** catch errors thrown in the root `app/layout.js` or `app/template.js` component. To specifically handle errors in these root components, use a variation of `error.js` called `app/global-error.js` located in the root `app` directory. Unlike the root `error.js`, the `global-error.js` error boundary wraps the **entire** application, and its fallback component replaces the root layout when active. Because of this, it is important to note that `global-error.js` **must** define its own `` and `` tags. `global-error.js` is the least granular error UI and can be considered "catch-all" error handling for the whole application. It is unlikely to be triggered often as root components are typically less dynamic, and other `error.js` boundaries will catch most errors. Even if a `global-error.js` is defined, it is still recommended to define a root `error.js` whose fallback component will be rendered **within** the root layout, which includes globally shared UI and branding. ```tsx filename="app/global-error.tsx" switcher 'use client' export default function GlobalError({ error, reset, }: { error: Error reset: () => void }) { return (

Something went wrong!

) } ``` ```jsx filename="app/global-error.js" switcher 'use client' export default function GlobalError({ error, reset }) { return (

Something went wrong!

) } ``` ### Handling Server Errors If an error is thrown during [data fetching](/docs/app/building-your-application/data-fetching/fetching) or inside a Server Component, Next.js will forward the resulting `Error` object to the nearest `error.js` file as the `error` prop. When running `next dev`, the `error` will be serialized and forwarded from the Server Component to the client `error.js`. To ensure security when running `next start` in production, a generic error message is forwarded to `error` along with a `.digest` which contains a hash of the error message. This hash can be used to correspond to server logs.