Cannot GET / (Express / Node no matching route)

Express answered the HTTP request, but no route matched that method and path. The server is up — the URL is wrong or unregistered.

How it shows up

Cannot GET /
Cannot GET /api/users
Cannot POST /login

HTTP/1.1 404 Not Found
Content-Type: text/html; charset=utf-8
X-Powered-By: Express

You are past connect/TLS. curl gets a real HTTP response — just not the handler you expected.

What Express is saying

After the middleware stack runs, if nothing called res.send / next into a final handler, Express’s final handler sends a tiny HTML body: Cannot METHOD path. NestJS, some Fastify setups, and older Connect apps can print the same style of message.

vs lookalikes

Common causes

• No route registered — forgot app.get('/'), typo in path (/user vs /users), or router never app.use’d.
• Wrong HTTP method — browser GET to a POST-only endpoint → Cannot GET ….
• Mount path — app.use('/api', router) but you request / or /api/ vs /api inconsistently.
• Static files not mounted — missing express.static; asking for /app.js hits the 404 handler.
• Reverse proxy path — nginx forwards /api/foo but strips or doubles a prefix the app does not expect.
• SPA deep link — user refreshes on /dashboard; server has no such file/route. Need history-fallback to index.html.
• Listening on another process — old server without your new routes still bound (see EADDRINUSE).

Minimal fix patterns

import express from "express";
const app = express();

app.get("/", (_req, res) => res.send("ok"));
app.get("/api/health", (_req, res) => res.json({ ok: true }));

// JSON 404 instead of "Cannot GET …"
app.use((req, res) => {
  res.status(404).json({ error: "not_found", path: req.path, method: req.method });
});

app.listen(3000, "127.0.0.1");

# Confirm what answers
curl -sI http://127.0.0.1:3000/
curl -s http://127.0.0.1:3000/missing
# List listeners if the wrong app might be up
ss -ltnp | grep 3000

SPA fallback (careful order)

app.use(express.static("dist"));
app.get("*", (req, res, next) => {
  if (req.path.startsWith("/api")) return next();
  res.sendFile("index.html", { root: "dist" });
});
// then API 404 / error handlers

Put API routes before the * fallback so /api/… still 404s as JSON when missing.

Checklist

1. Log req.method + req.originalUrl on a catch-all to see what arrived (proxy prefixes included).
2. Verify the router is mounted: app.use('/api', apiRouter).
3. Match method and path exactly; trailing slashes matter unless you normalize them.
4. Replace the default HTML 404 with JSON for APIs.
5. If curl to the port works but the public URL 404s, fix the reverse-proxy location / proxy_pass path.

Related

Invalid hook call (React) · localhost refused to connect · EADDRINUSE address already in use · 502 Bad Gateway · TypeError: Failed to fetch · CORS errors explained · Anvil HTTP status · Anvil URL inspect

Questions

Published 6 November 2026.