router-core/not-found-and-errors

To handle 404 not-found errors in TanStack Router, throw the notFound() function inside your loader when a resource is missing, then configure a notFoundComponent on the route to render a friendly not-found UI boundary.

Global not-found handling uses a notFoundComponent on the root route for default 404 UI, while per-route not-found handling throws notFound() inside specific loaders to trigger route-specific not-found boundaries.

Assign an errorComponent to your route to display loader errors in TanStack Router. This error boundary catches loader failures and allows users to retry the request via router.invalidate().

Yes, TanStack Router supports controlling not-found propagation across nested routes using the notFoundMode configuration, which offers fuzzy or root modes to manage how 404 boundaries propagate.

You should avoid useLoaderData in notFoundComponent because it follows safe data patterns. Instead, use Route.useParams, useSearch, or the data option to safely access parameters without relying on potentially missing loader data.

Yes, TanStack Router supports route masking alongside not-found and error handling, allowing you to mask route URLs while configuring notFoundComponent and errorComponent for graceful degradation.