Langfuse
Editor Verified Open SourceOpen-source LLM engineering platform for tracing, evaluations, prompt management, and metrics.
Last Verified: February 2026 • Open Source
Free Tier Boundaries & Verification
Verified Free Allowance:
100% free and open-source self-hosted under MIT license; Cloud Hobby plan provides 50,000 ingested traces/month with 30-day retention.
Commercial Entry Price: Cloud Pro starts at $59/month for 100k+ traces, or self-host free on your own infrastructure.
Check Live Pricing Matrix Architecture & Purpose
Langfuse is an open-source LLM observability and evaluation platform that helps engineering teams monitor cost, latency, quality, and user feedback across complex agentic chains and LLM applications.
Target Audience & ICP:
AI engineers, LLM application developers, and engineering leads needing transparent tracing and prompt versioning.
Practical Use Cases
- Tracing nested agent tool calls, reasoning loops, and prompt chains in real-time.
- Managing prompt templates in code with semantic versioning without Git redeploys.
- Running automated model evaluation benchmarks against production trace datasets.
Key Capabilities & Features
- Full trace waterfall diagrams with span-level latency and token consumption metrics.
- SDK integrations for LangChain, LlamaIndex, OpenAI, Anthropic, and custom agents.
- Complete Docker compose and Kubernetes Helm charts for self-hosted deployment.
Known Limitations & Operational Tradeoffs
- • Self-hosting requires administering PostgreSQL and ClickHouse database clusters.
Side-by-Side Alternatives Comparison
Direct Market Counterparts| Specification | Langfuse
Active
| LangSmith Alternative |
|---|---|---|
| Pricing Model | Open Source | Generous Free Tier |
| Free Tier Boundaries | 100% free and open-source self-hosted under MIT license; Cloud Hobby plan provides 50,000 ingested traces/month with 30-day retention. | 5,000 traces/month on free tier |
| Commercial Pricing | Cloud Pro starts at $59/month for 100k+ traces, or self-host free on your own infrastructure. | $39/seat/month |
| Core Moat / Strength | 100% open-source transparency eliminates data privacy concerns for sensitive customer queries. | Proprietary LangChain observability competitor |
| Known Limitation | Self-hosting requires administering PostgreSQL and ClickHouse database clusters. | Subject to provider rate limits. |
| Official Site | Visit Langfuse | Visit LangSmith |