Langfuse

Open-source LLM observability and engineering platform for tracing, evaluation, and prompt management

by Langfuse (ClickHouse)

Germany🌐EU (Ireland — AWS eu-west-1) or US; self-hosted anywhere

AI Agents & Orchestration DevOps & Infrastructure

TrustKit ScoreRated across 5 compliance dimensions: data residency, legal jurisdiction, data retention, certifications, and regulatory fit.Excellent

About Langfuse

Langfuse was founded in 2023 in Berlin by Marc Klingen, Max Deichmann, and Clemens Rawert as part of Y Combinator's W23 batch. The platform provides open-source LLM observability: tracing of every LLM call, prompt management, LLM-as-a-judge evaluation, dataset management, and custom dashboards for monitoring production AI applications. The platform integrates with the major AI development frameworks including OpenTelemetry, LangChain, OpenAI SDK, and LiteLLM. With over 20,000 GitHub stars and 26 million+ SDK installs per month, Langfuse has become one of the most widely adopted open-source LLM engineering tools, used by 19 of the Fortune 50 and 63 of the Fortune 500. In January 2026, Langfuse was acquired by ClickHouse as part of ClickHouse's $400 million Series D round. The product continues to operate as an open-source project. For European businesses, Langfuse offers a strong compliance and data sovereignty posture. The cloud product offers an EU region (AWS eu-west-1, Ireland) where customer data stays within the EEA. Langfuse explicitly does not train or fine-tune models on customer data. The platform holds SOC 2 Type II and ISO 27001 certifications, with GDPR DPA and HIPAA BAA available. Critically, Langfuse is fully open-source and can be self-hosted on any infrastructure—Docker, Kubernetes, or air-gapped environments—giving European organisations complete control over their LLM observability data without any dependency on Langfuse's cloud infrastructure.

TrustKit Score Breakdown

?88% Excellent

Data Residency

Where is your data stored and processed?

EU cloud region (Ireland) keeps data within EEA. Full self-hosting option allows air-gapped EU deployments with zero cloud dependency. Customer can choose exact data location.

5/5

Legal Jurisdiction

Which laws govern the company and your data?

German GmbH (EU company) but acquired by ClickHouse Inc. (US). German law governs the entity but US parent introduces CLOUD Act considerations. Self-hosted deployment eliminates US cloud dependency.

3/5

Data Retention & Training

Is your data used for model training?

Explicitly does not train on customer data. Customer traces and prompts processed solely to provide the service. Self-hosted gives full data lifecycle control.

5/5

Certifications

ISO 27001, SOC 2, Cyber Essentials, etc.

SOC 2 Type II and ISO 27001 certified with annual audits. HIPAA BAA available. Annual external penetration tests. Excellent certification posture for a developer tooling company.

5/5

Regulatory Fit

Suitability for regulated industries and professional services

EU data hosting, GDPR DPA, German legal origin, self-hosting for regulated industries. HIPAA compliance extends reach to healthcare. The ClickHouse acquisition is the main caveat for sovereignty purists.

4/5

Pricing

FreemiumFree tier

HobbyFree50K observations/month · Tracing and debugging · Prompt management

Pro$59/moUnlimited observations · Evaluation pipelines · SSO · …

EnterpriseFreeSelf-hosted deployment · GDPR DPA · HIPAA BAA · …

Full pricing details →

Quick Facts

Starting PriceFree (self-hosted) / Free cloud tierData HostingEU (Ireland — AWS eu-west-1) or US; self-hosted anywhereTrains on Your DataExplicitly does not train on customer dataFounded2023Employees11-50

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Frequently Asked Questions

Is Langfuse GDPR compliant?

Langfuse has a TrustKit compliance score of 88% (Excellent). Data Residency: EU cloud region (Ireland) keeps data within EEA. Full self-hosting option allows air-gapped EU deployments with zero cloud dependency. Customer can choose exact data location.. Legal Jurisdiction: German GmbH (EU company) but acquired by ClickHouse Inc. (US). German law governs the entity but US parent introduces CLOUD Act considerations. Self-hosted deployment eliminates US cloud dependency..

Where does Langfuse store data?

Langfuse hosts data in: EU (Ireland — AWS eu-west-1) or US; self-hosted anywhere. EU cloud region (Ireland) keeps data within EEA. Full self-hosting option allows air-gapped EU deployments with zero cloud dependency. Customer can choose exact data location.

Does Langfuse train on user data?

Langfuse: Explicitly does not train on customer data. Explicitly does not train on customer data. Customer traces and prompts processed solely to provide the service. Self-hosted gives full data lifecycle control.

What certifications does Langfuse hold?

Langfuse holds: SOC 2 Type II, ISO 27001. SOC 2 Type II and ISO 27001 certified with annual audits. HIPAA BAA available. Annual external penetration tests. Excellent certification posture for a developer tooling company.