Open-source alternatives to Prometheus

Prometheus is itself a widely used open-source metrics and monitoring system (Apache-2.0, part of the CNCF), so it isn't something you need to replace for licensing reasons. What people usually look for alongside it is a visualization layer or a complementary tool for workloads Prometheus wasn't designed for, like LLM-specific observability.

Grafana is the standard visualization layer paired with Prometheus, turning its metrics into dashboards, and is also open source. If your monitoring target is specifically LLM or AI agent behavior rather than general infrastructure metrics, OpenLIT is built for that instead.

FAQ

Is there a free, open-source alternative to Prometheus?

Prometheus is already free and open source. Grafana is the open-source dashboarding layer most commonly paired with it, and OpenLIT covers LLM-specific observability that Prometheus wasn't built for.

What's the best tool to pair with Prometheus?

Grafana is the standard choice for visualizing Prometheus metrics. OpenLIT is the better pick when you need tracing and cost tracking for LLM calls specifically.

What are the top open-source tools in this space?

Browse all open-source alternatives to Prometheus above, or explore the full Analytics category for more options.