Vue provides onErrorCaptured to catch errors from descendant components, letting you build error boundaries similar to React's componentDidCatch. Combined with app.config.errorHandler for global errors and defineAsyncComponent's error options, you can handle failures at every level.

onErrorCaptured (error boundary)

A parent component can catch errors thrown by any descendant (including async errors from lifecycle hooks and watchers):

<!-- ErrorBoundary.vue -->
<script setup>
import { ref, onErrorCaptured } from 'vue'

const error = ref<Error | null>(null)

onErrorCaptured((err, instance, info) => {
  error.value = err
  console.error(`Error in ${info}:`, err)
  return false // stop propagation to parent error handlers
})
</script>

<template>
  <div v-if="error" class="error-state">
    <p>Something went wrong: {{ error.message }}</p>
    <button @click="error = null">Try again</button>
  </div>
  <slot v-else />
</template>

<!-- Usage -->
<template>
  <ErrorBoundary>
    <DashboardWidget />
  </ErrorBoundary>
</template>

The callback receives three arguments:

Argument	Description
err	The error object
instance	The component instance that threw
info	A string describing where the error was caught (e.g., "render", "setup", "watcher")

Returning false prevents the error from propagating further. Returning true (or nothing) lets it bubble up to parent error handlers and app.config.errorHandler.

Global error handler

Catches any error that wasn't stopped by onErrorCaptured:

// main.ts
const app = createApp(App)

app.config.errorHandler = (err, instance, info) => {
  // Send to error tracking service
  errorTracker.captureException(err, { info })
}

Error flow

Component throws → nearest onErrorCaptured (can stop here)
                 → parent onErrorCaptured (can stop here)
                 → ... up the tree ...
                 → app.config.errorHandler
                 → console.error (if nothing catches it)

Async component errors

defineAsyncComponent has its own error handling with retry logic:

const AsyncWidget = defineAsyncComponent({
  loader: () => import('./Widget.vue'),
  errorComponent: ErrorDisplay,
  timeout: 10000,
  onError(error, retry, fail, attempts) {
    if (attempts <= 3) {
      retry()
    } else {
      fail() // shows errorComponent
    }
  }
})

What Vue error handling catches

Source	Caught?
Render/template errors	Yes
Lifecycle hook errors	Yes
Watcher callback errors	Yes
Component event handler errors	Yes
Custom directive hook errors	Yes
setTimeout/setInterval callbacks	No (not tracked by Vue)
Native event listeners added manually	No
Errors in third-party libraries	No (unless called from Vue lifecycle)

For errors outside Vue's tracking (timers, manual listeners), use window.addEventListener('error', handler) or window.addEventListener('unhandledrejection', handler).

Practical pattern: multiple error boundaries

Wrap independent sections so one failure doesn't take down the whole page:

<template>
  <header>
    <ErrorBoundary>
      <Navigation />
    </ErrorBoundary>
  </header>

  <main>
    <ErrorBoundary>
      <RouterView />
    </ErrorBoundary>
  </main>

  <aside>
    <ErrorBoundary>
      <Sidebar />
    </ErrorBoundary>
  </aside>
</template>