Node.js Diagnostic

Fix "Error: connect ECONNREFUSED 127.0.0.1:port" in Node.js & Databases

The target host IP and port actively rejected the TCP handshake. This means no service or database is listening on that port, or Node is attempting IPv6 (::1) while the service listens on IPv4 (127.0.0.1).

Error: connect ECONNREFUSED 127.0.0.1:5432 / :::3000

Quick Fix Checklist

  1. Verify target database is running: sudo systemctl status postgresql (or docker ps)
  2. Change "localhost" to "127.0.0.1" in your connection string to force IPv4
  3. Inside Docker containers: Use "host.docker.internal" instead of "localhost" to contact host machine