Nuxt/docs/3.api/3.utils/define-nuxt-route-middleware.md
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---
title: "defineNuxtRouteMiddleware"
description: "Create named route middleware using defineNuxtRouteMiddleware helper function."
links:
- label: Source
icon: i-simple-icons-github
to: https://github.com/nuxt/nuxt/blob/main/packages/nuxt/src/app/composables/router.ts
size: xs
---
Route middleware are stored in the [`middleware/`](/docs/guide/directory-structure/middleware) of your Nuxt application (unless [set otherwise](/docs/api/nuxt-config#middleware)).
## Type
```ts
defineNuxtRouteMiddleware(middleware: RouteMiddleware) => RouteMiddleware
interface RouteMiddleware {
(to: RouteLocationNormalized, from: RouteLocationNormalized): ReturnType<NavigationGuard>
}
```
## Parameters
### `middleware`
- **Type**: `RouteMiddleware`
A function that takes two Vue Router's route location objects as parameters: the next route `to` as the first, and the current route `from` as the second.
Learn more about available properties of `RouteLocationNormalized` in the **[Vue Router docs](https://router.vuejs.org/api/interfaces/RouteLocationNormalized.html)**.
## Examples
### Showing Error Page
You can use route middleware to throw errors and show helpful error messages:
```ts [middleware/error.ts]
export default defineNuxtRouteMiddleware((to) => {
if (to.params.id === '1') {
throw createError({ statusCode: 404, statusMessage: 'Page Not Found' })
}
})
```
The above route middleware will redirect a user to the custom error page defined in the `~/error.vue` file, and expose the error message and code passed from the middleware.
### Redirection
Use [`useState`](/docs/api/composables/use-state) in combination with `navigateTo` helper function inside the route middleware to redirect users to different routes based on their authentication status:
```ts [middleware/auth.ts]
export default defineNuxtRouteMiddleware((to, from) => {
const auth = useState('auth')
if (!auth.value.isAuthenticated) {
return navigateTo('/login')
}
if (to.path !== '/dashboard') {
return navigateTo('/dashboard')
}
})
```
Both [navigateTo](/docs/api/utils/navigate-to) and [abortNavigation](/docs/api/utils/abort-navigation) are globally available helper functions that you can use inside `defineNuxtRouteMiddleware`.