Langfuse
Langfuse GmbH
Open Source LLM Engineering Platform
Last verified April 24, 2026About Langfuse
Langfuse is an open-source LLM observability platform that provides tracing, evaluations, prompt management, and analytics for debugging and improving LLM applications and agents. Key differentiators include model/framework-agnostic SDKs, OpenTelemetry compatibility, self-hosting option, and integrated workflow for observability, experiments, and human annotation. Typical buyers are AI engineering teams at startups to Fortune 50 companies developing production AI products. Notable: Acquired by ClickHouse in January 2026; supports compliance certifications like SOC 2 Type II, ISO 27001, GDPR, HIPAA eligible.
Framework coverage
Capabilities
Features Langfuse markets publicly. Inclusion means the capability is documented — not that it's best-in-class.
Model Monitoring
Production monitoring for performance, drift, data quality, and fairness regressions.
LLM Evaluation
Systematic testing of LLM outputs for correctness, relevance, safety, and consistency using automated scorers, rubrics, or human review.
Prompt Management
Versioning, templating, A/B testing, and deployment workflows for LLM prompts treated as production artifacts.
Agent Tracing
End-to-end visibility into multi-step LLM agent runs: tool calls, intermediate reasoning, token usage, latency, and errors at each step.
Drift Detection
Automated detection of distribution shift, feature drift, prediction drift, and performance degradation in deployed ML/AI models.
Integrations
Documented by Langfuse in public product materials.
- OpenAI API
- Anthropic API
- LangChain
- LlamaIndex
- Vercel AI SDK
- LiteLLM
- CrewAI
- Amazon Bedrock
- Azure OpenAI Service
- Mistral AI
- Groq
- GitHub
Pricing
Contact for pricing
Hobby free forever; Core $29/mo, Pro $199/mo, Enterprise $2499/mo; all include 100k units/mo (50k for Hobby), additional usage $8/100k units decreasing with volume; discounts for startups/OSS/EDU.
Pros and cons
Pros
- Open-source core under MIT license with self-hosting support.
- Extensive integrations with 80+ frameworks/providers including LangChain, OpenAI, Anthropic.
- Production-scale reliability processing billions of observations monthly.
- Compliance-ready with SOC 2 Type II, ISO 27001, GDPR, HIPAA eligible.
Cons
- No public documentation of support for AI regulatory frameworks like EU AI Act or NIST AI RMF.
- Limited independent analyst coverage or customer reviews on sites like G2 (0 reviews).
- Employee count small relative to enterprise ambitions.
- Recent acquisition by ClickHouse may signal strategic shifts.
Frequently asked
Is Langfuse open source?+
Yes, core features including tracing, evals, and prompt management are open source under MIT license.
What is a pricing unit?+
Units track traces/observations; plans include monthly allowances with overage at $8/100k decreasing by volume.
Can I self-host Langfuse?+
Yes, fully self-hostable in minutes using Docker; battle-tested at production scale.
What compliance does it support?+
SOC 2 Type II, ISO 27001, GDPR compliant, HIPAA eligible, EU/US data regions.
Sources
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