Open-Source AI · LLM / RAG framework

Ragas vs Langfuse

Ragas vs Langfuse compared for 2026 — features, license, ease of use, performance and which one to choose. Measure whether your RAG is any good vs See what your LLM app actually did.

Updated regularly · curated by OpenSourceAI.tech

Choose Ragas for anyone tuning a RAG pipeline blind. Choose Langfuse for debugging and monitoring LLM apps in production.

Ragas vs Langfuse at a glance

Spec	Ragas	Langfuse
Category	LLM / RAG framework	LLM / RAG framework
Type	RAG evaluation	LLM observability
License	Apache-2.0	MIT
Runs locally	Yes	Yes
Primary language	Python	TypeScript
Ease of use	Intermediate	Intermediate
Best for	anyone tuning a RAG pipeline blind	debugging and monitoring LLM apps in production
GitHub stars	—	31.3k

How Ragas and Langfuse score

🤝 Too close to call — Ragas and Langfuse land within a hair (4.5 vs 4.5 / 5). Pick on fit, not on score.

Criterion	Ragas	Langfuse
Popularity	n/a	4.0
Maintenance	n/a	5.0
Ease of use	3.5	3.5
Privacy	5.0	5.0
License freedom	5.0	5.0

Scores are computed automatically from public signals — GitHub stars (popularity), recent commit activity (maintenance), license type (freedom), local-first design (privacy) and onboarding complexity (ease of use). Indicative, not a verdict.

What each one is

Ragas

RAG evaluation · Apache-2.0

Ragas scores RAG pipelines on faithfulness, answer relevance and context precision, turning "it feels better" into numbers.

Objective RAG quality metrics
Catches hallucinations quantitatively
Integrates with LangChain and LlamaIndex

Visit Ragas →

Langfuse

LLM observability · MIT

Langfuse traces every LLM call, tool use and cost in your application, with prompt management and evaluation built in — self-hostable.

Full tracing of chains and agents
Cost and latency tracking
Self-hosted, MIT licensed

See the Langfuse page →

Key differences

Ragas is rAG evaluation, while Langfuse is lLM observability. Their licenses differ (Apache-2.0 vs MIT), which matters if you ship a commercial product. In short, Ragas fits anyone tuning a RAG pipeline blind, and Langfuse fits debugging and monitoring LLM apps in production.

Which should you choose?

Choose Ragas for anyone tuning a RAG pipeline blind. Choose Langfuse for debugging and monitoring LLM apps in production.

There is rarely one winner — many setups use both. The right pick depends on your hardware, your team's skills, and whether you value simplicity or control.

Frequently asked questions

Is Ragas or Langfuse easier to use?

Both sit at a similar level (Intermediate). Your choice should come down to fit rather than difficulty.

Are Ragas and Langfuse free?

Ragas is free and open source (Apache-2.0), and Langfuse is free and open source (MIT). Neither charges for the core software.

Can I run Ragas and Langfuse locally?

Ragas: yes · Langfuse: yes. Both can be used without sending your data to a third-party cloud where their setup allows.

Ragas vs Langfuse — which should I pick in 2026?

Choose Ragas for anyone tuning a RAG pipeline blind. Choose Langfuse for debugging and monitoring LLM apps in production.

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