Langfuse ranks #2 in LLM Observability Evals & Gateways AI search.

Langfuse is an open-source LLM engineering platform, founded in 2022 and acquired by ClickHouse in January 2026, that helps development teams build, monitor, and continuously improve AI applications and agents. Licensed under MIT and self-hostable via Docker or Kubernetes, the platform consolidates LLM observability (tracing), prompt management, evaluation, and experimentation into a single integrated workflow. It processes over 10 billion observations per month, serves 2,300+ customers including 19 of the Fortune 50, and has accumulated more than 26,000 GitHub stars with 300+ contributors. Langfuse is OpenTelemetry-native, framework-agnostic across 80+ integrations, and is backed by a ClickHouse OLAP architecture built for high-throughput ingestion and millisecond-scale analytics at enterprise scale.

Langfuse is an open-source, MIT-licensed LLM engineering platform that provides end-to-end tooling for the full AI application development lifecycle: hierarchical trace-based observability, versioned prompt management with one-click deploys, multi-method evaluation (LLM-as-a-judge, human annotation, user feedback, custom pipelines), structured experiment comparison, and cost/latency/quality analytics dashboards. It is OpenTelemetry-native, integrates with 80+ frameworks and model providers, and can be deployed on Langfuse Cloud or self-hosted on Docker, Kubernetes, AWS, GCP, or Azure. Since its January 2026 acquisition by ClickHouse, Langfuse runs on a ClickHouse OLAP backend enabling millisecond-latency queries over billions of monthly observations.