Error Handling

Handling errors

Nuxt 3 is a full-stack framework, which means there are several sources of unpreventable user runtime errors that can happen in different contexts:

  1. Errors during the Vue rendering lifecycle (SSR + SPA)
  2. Errors during API or Nitro server lifecycle
  3. Server and client startup errors (SSR + SPA)

Errors during the Vue rendering lifecycle (SSR + SPA)

You can hook into Vue errors using onErrorCaptured.

In addition, Nuxt provides a vue:error hook that will be called if any errors propagate up to the top level.

If you are using an error reporting framework, you can provide a global handler through vueApp.config.errorHandler. It will receive all Vue errors, even if they are handled.

Example with global error reporting framework

export default defineNuxtPlugin((nuxtApp) => {  nuxtApp.vueApp.config.errorHandler = (error, context) => {    // ...  }})

Server and client startup errors (SSR + SPA)

Nuxt will call the app:error hook if there are any errors in starting your Nuxt application.

This includes:

  • running Nuxt plugins
  • processing app:created and app:beforeMount hooks
  • mounting the app (on client-side), though you should handle this case with onErrorCaptured or with vue:error
  • processing the app:mounted hook

Errors during API or Nitro server lifecycle

You cannot currently define a server-side handler for these errors, but can render an error page (see the next section).

Rendering an error page

When Nuxt encounters a fatal error, whether during the server lifecycle, or when rendering your Vue application (both SSR and SPA), it will either render a JSON response (if requested with Accept: application/json header) or an HTML error page.

You can customize this error page by adding ~/error.vue in the source directory of your application, alongside app.vue. This page has a single prop - error which contains an error for you to handle.

When you are ready to remove the error page, you can call the clearError helper function, which takes an optional path to redirect to (for example, if you want to navigate to a 'safe' page).

Example

<template>  <button @click="handleError">Clear errors</button></template><script setup>const props = defineProps({  error: Object})const handleError = () => clearError({ redirect: '/' })</script>

Error helper methods

useError

  • function useError (): Ref<any>

This function will return the global Nuxt error that is being handled.

createError

  • function createError (err: { cause, data, message, name, stack, statusCode, statusMessage, fatal }): Error

You can use this function to create an error object with additional metadata. It is usable in both the Vue and Nitro portions of your app, and is meant to be thrown.

If you throw an error created with createError:

  • on server-side, it will trigger a full-screen error page which you can clear with clearError.
  • on client-side, it will throw a non-fatal error for you to handle. If you need to trigger a full-screen error page, then you can do this by setting fatal: true.

Example

In the current version, add import { createError } from 'h3' in order to use createError.

<script setup>const route = useRoute()const { data } = await useFetch(`/api/movies/${route.params.slug}`)if (!data.value) {  throw createError({ statusCode: 404, statusMessage: 'Page Not Found' })}</script>

showError

In the current version, use throwError or throw createError instead.

  • function showError (err: string | Error | { statusCode, statusMessage }): Error

You can call this function at any point on client-side, or (on server side) directly within middleware, plugins or setup() functions. It will trigger a full-screen error page which you can clear with clearError.

It is recommended instead to use throw createError().

clearError

  • function clearError (options?: { redirect?: string }): Promise<void>

This function will clear the currently handled Nuxt error. It also takes an optional path to redirect to (for example, if you want to navigate to a 'safe' page).

Rendering errors within your app

Nuxt also provides a <NuxtErrorBoundary> component that allows you to handle client-side errors within your app, without replacing your entire site with an error page.

This component is responsible for handling errors that occur within its default slot. On client-side, it will prevent the error from bubbling up to the top level, and will render the #error slot instead.

The #error slot will receive error as a prop. (If you set error = null it will trigger re-rendering the default slot; you'll need to ensure that the error is fully resolved first or the error slot will just be rendered a second time.)

Example

<template>  <!-- some content -->  <NuxtErrorBoundary @error="someErrorLogger">    <!-- You use the default slot to render your content -->    <template #error="{ error }">      You can display the error locally here.      <button @click="error = null">        This will clear the error.      </button>    </template>  </NuxtErrorBoundary></template>