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req.hostname

The hostname derived from the Host (or X-Forwarded-Host) header.

Since Express 4 Spec ↗

Syntax

req.hostname

Returns

string — The request hostname without the port.

Examples

app.get('/host', (req, res) => {
  res.send(req.hostname);
});
Output 
$ curl -H 'Host: api.example.com' localhost:3000/host
api.example.com

app.use((req, res, next) => {
  if (req.hostname === 'admin.example.com') req.isAdminHost = true;
  next();
});

Notes

Strips the port. When `trust proxy` is enabled Express uses `X-Forwarded-Host`. Validate or whitelist expected hostnames if you branch logic on it, since the Host header is client-controlled.

See also