Nginx Proxy Manager 502 Bad Gateway checklist
A focused checklist for a 502 Bad Gateway error after adding a proxy host in Nginx Proxy Manager.
First checks
- Confirm the upstream app responds from the VPS or Docker network on the exact host and port configured in Nginx Proxy Manager.
- Check whether the proxy host should use HTTP or HTTPS to the upstream service before toggling Force SSL.
- Verify the container network name, exposed port, and health logs before changing Cloudflare DNS again.
- Retest with Cloudflare paused or DNS-only if the origin works locally but the public hostname still returns 502.
Free helper
Map the upstream protocol, Docker network, port, WebSocket, and timeout symptoms before changing DNS again.
Paid pack
Get the private Cloudflare/Nginx launch checklist and rollback notes for future deployments.
Operational checklist only. Confirm hosting, firewall, DNS, and Cloudflare settings in your own provider dashboards. Short checkout: https://buy.signal-shelf.com/cloudflare.