TanStack Start React Docs

Error Boundaries (React Start)

TanStack Start uses TanStack Router's route-level error boundaries.

Set a default for all routes via the router
Override per-route with errorComponent

Configure a default

tsx

// src/router.tsx
import { createRouter, ErrorComponent } from '@tanstack/react-router'
import { routeTree } from './routeTree.gen'

export function getRouter() {
  const router = createRouter({
    routeTree,
    // Shown when an error bubbles to the router
    defaultErrorComponent: ({ error, reset }) => (
      <ErrorComponent error={error} />
    ),
  })
  return router
}

// src/router.tsx
import { createRouter, ErrorComponent } from '@tanstack/react-router'
import { routeTree } from './routeTree.gen'

export function getRouter() {
  const router = createRouter({
    routeTree,
    // Shown when an error bubbles to the router
    defaultErrorComponent: ({ error, reset }) => (
      <ErrorComponent error={error} />
    ),
  })
  return router
}

Per-route override

tsx

// src/routes/posts.$postId.tsx
import { createFileRoute, ErrorComponent } from '@tanstack/react-router'
import type { ErrorComponentProps } from '@tanstack/react-router'

function PostError({ error, reset }: ErrorComponentProps) {
  return <ErrorComponent error={error} />
}

export const Route = createFileRoute('/posts/$postId')({
  component: PostComponent,
  errorComponent: PostError,
})

// src/routes/posts.$postId.tsx
import { createFileRoute, ErrorComponent } from '@tanstack/react-router'
import type { ErrorComponentProps } from '@tanstack/react-router'

function PostError({ error, reset }: ErrorComponentProps) {
  return <ErrorComponent error={error} />
}

export const Route = createFileRoute('/posts/$postId')({
  component: PostComponent,
  errorComponent: PostError,
})

Notes:

ErrorComponent is a simple built-in UI you can replace.
Call reset() to retry rendering the route after fixing state.
Use beforeLoad/loader to throw errors that will be caught.