Port 9090: Prometheus

Port 9090 is the default web interface and API port for Prometheus, the open-source metrics and monitoring system. Individual exporters that feed data into Prometheus typically run on their own ports, such as 9100 for the Node Exporter.

TCPWebUnencrypted by default
Port number9090
ServicePrometheus monitoring web UI
ProtocolTCP
CategoryWeb
Default encryptionNo
Security note. Port 9090 is not encrypted by default. Restrict it to trusted networks, or use an encrypted alternative where one exists, to avoid exposing credentials and data in transit.

Frequently asked questions

What is port 9090 used for?

Port 9090 is the default web interface and API port for Prometheus, the open-source metrics and monitoring system. Individual exporters that feed data into Prometheus typically run on their own ports, such as 9100 for the Node Exporter.

Is port 9090 TCP or UDP?

Port 9090 (Prometheus) uses TCP.

Is port 9090 secure?

Port 9090 is not encrypted by default. Where possible, use an encrypted alternative or tunnel it over TLS or a VPN.

Should I open port 9090 on my firewall?

Only if you specifically need Prometheus. Expose it to the smallest set of trusted sources, and never open database or Windows-service ports to the whole internet.