jsschools

req.ip

The remote IP address of the request.

Since Express 4 Spec ↗

Syntax

req.ip  /  req.ips

Returns

string — The client IP; req.ips is the X-Forwarded-For chain when trust proxy is set.

Examples

app.get('/whoami', (req, res) => {
  res.send(req.ip);
});
Output 
$ curl localhost:3000/whoami
::1

app.set('trust proxy', 1);

app.get('/ips', (req, res) => {
  res.json({ ip: req.ip, chain: req.ips });
});
Output 
{"ip":"203.0.113.5","chain":["203.0.113.5"]}

Notes

Behind a proxy or load balancer `req.ip` is the proxy address unless you set `app.set('trust proxy', ...)` so Express reads `X-Forwarded-For`. Only trust that header for proxies you control, since clients can forge it.

See also