remix-run/react-router · error · Error

No handlers were found for the request: ${url.pathname}${url

Error message

No handlers were found for the request: ${url.pathname}${url.search}

What it means

Thrown by the SSR request handler used during `vite preview` (and internal prerender requests). The handler iterates candidate request handlers from the server build; if every handler returns a 404 (or returns nothing), no handler matched the request URL, and the throw surfaces the unmatched `pathname` + `search`. It is the preview-mode equivalent of an unhandled route.

Source

Thrown at packages/react-router-dev/vite/plugin.ts:1720

                  (a, b) => b.matchDepth - a.matchDepth || a.index - b.index,
                )
                .map(({ entry }) => entry);
            }

            for (let { handler } of handlersToTry) {
              response = await handler(request, loadContext);

              if (response.status !== 404) {
                return response;
              }
            }

            if (response) {
              return response;
            }

            let url = new URL(request.url);
            throw new Error(
              "No handlers were found for the request: " +
                url.pathname +
                url.search,
            );
          };

          return cachedHandler;
        }

        return () => {
          // Handle SSR requests in preview mode using the built server bundle
          previewServer.middlewares.use(async (req, res, next) => {
            if (
              !ctx.reactRouterConfig.ssr &&
              (!process.env.hasOwnProperty("IS_RR_BUILD_REQUEST")
                ? true
                : process.env.IS_RR_BUILD_REQUEST !== "yes")
            ) {

View on GitHub (pinned to 1fd704a7da)

Solutions

1. Confirm the path is declared in your routes (`flatRoutes()` glob or manual `route()`).
2. Check `basename` in your config matches the URL prefix you are visiting.
3. Add a catch-all or resource route for paths external tools hit (e.g. `route("favicon.ico", ...)`).
4. Inspect your `serverBundles` function — make sure it does not omit the branch serving this path.
5. If prerendering, ensure the path is listed in `prerender` or matched by a route.

Example fix

// before: /favicon.ico returns "No handlers were found"
// after: add a resource route
// app/routes/favicon[.]ico.ts
export const loader = () =>
  new Response(favicon, { headers: { "content-type": "image/x-icon" } });

// Validate a path is addressable before preview
import { matchRoutes } from "react-router";
const assertRoutable = (routes, pathname) => {
  if (!matchRoutes(routes, pathname)) {
    throw new Error(`No route matches ${pathname}`);
  }
};

try {
  await handler(request);
} catch (e) {
  if (/No handlers were found/.test(String(e.message))) {
    // serve a custom 404 instead of crashing preview
    return new Response(notFoundHtml, { status: 404, headers: { "content-type": "text/html" } });
  }
  throw e;
}

When it happens

Trigger: Hitting a path during `react-router preview` that is not in the route manifest (e.g. `/favicon.ico` when no route or static file serves it); a misconfigured `basename` so requests resolve against the wrong prefix; a deployed server bundle missing the route because `serverBundles` filtered it out; SPA fallback disabled and the path matches no static asset either.

Common situations: Previewing a prerendered build and visiting a URL that was neither prerendered nor routed; misaligned `basename` between build and preview; tooling/bots requesting `/robots.txt` or `/_health` that have no handler; `serverBundles` accidentally excludes a branch.

Related errors

• Unable to prerender path because it does not match any route
• Unable to define routes with duplicate route id: "${id}"
• Custom Vite manifest paths are not supported
• The "serverBundles" function must return a string
• Prerender (data): Received a ${response.status} status code

AI-assisted analysis of remix-run/react-router@1fd704a7da (2026-08-12). Data as JSON: /api/errors/d8591342e62de90b. Report an issue: GitHub.