# Errors

> Error pages, and what API clients get.

## The error page

An unknown URL, a `throw new HTTPException(403)` or an error in a handler: a page request gets `app/pages/error.tsx`
with the status, inside the layout, with the shared props. API clients get plain text, or the `HTTPException`'s own
response.

```tsx
// app/pages/error.tsx
export default function ErrorPage({ status }: { status: number }) {
  return <h1>{status === 404 ? 'Page not found' : 'Something went wrong'}</h1>
}
```

Another page: `createApp({ errorPage: 'errors/show' })`. None, plain text for everyone: `errorPage: false`.

## In development

A 500 is a report of the error instead: the message, and the stack with your files first. During a visit, Inertia
shows it in its dialog. And `render()` of a page that doesn't exist says which file to create.

## Your own handling

`createApp()` returns a Hono app: its `notFound()` and `onError()` replace Fondu's.

```ts
const app = createApp()

app.onError((error, c) => {
  report(error)
  return c.text('Something went wrong', 500)
})

export default app
```