Keywords AI

Langfuse vs Ragas

Compare Langfuse and Ragas side by side. Both are tools in the Observability, Prompts & Evals category.

Quick Comparison

Langfuse
Langfuse
Ragas
Ragas
CategoryObservability, Prompts & EvalsObservability, Prompts & Evals
PricingOpen SourceOpen Source
Best ForTeams who want open-source LLM observability they can self-host and customizeDevelopers building RAG applications who need specialized evaluation metrics
Websitelangfuse.comragas.io
Key Features
  • Open-source LLM observability
  • Detailed trace and span tracking
  • Prompt management
  • Evaluation scoring
  • Self-hosted and cloud options
  • RAG-specific evaluation framework
  • Component-wise metrics for RAG
  • Synthetic test data generation
  • LLM-as-judge evaluators
  • Open-source Python library
Use Cases
  • Self-hosted LLM monitoring
  • Open-source tracing for AI applications
  • Prompt versioning and management
  • Cost tracking across providers
  • Community-driven observability
  • Evaluating RAG pipeline quality end-to-end
  • Measuring retrieval precision and recall
  • Testing faithfulness and answer relevance
  • Generating synthetic evaluation datasets
  • Benchmarking RAG across configurations

When to Choose Langfuse vs Ragas

Langfuse
Choose Langfuse if you need
  • Self-hosted LLM monitoring
  • Open-source tracing for AI applications
  • Prompt versioning and management
Pricing: Open Source
Ragas
Choose Ragas if you need
  • Evaluating RAG pipeline quality end-to-end
  • Measuring retrieval precision and recall
  • Testing faithfulness and answer relevance
Pricing: Open Source

About Langfuse

Langfuse is an open-source LLM observability platform that provides tracing, analytics, prompt management, and evaluation for AI applications. It captures detailed traces of LLM calls, supports custom scoring, and integrates with LangChain, LlamaIndex, Vercel AI SDK, and raw API calls. Langfuse can be self-hosted for data privacy or used as a managed cloud service. Its open-source model and generous free tier make it popular with startups and developers.

About Ragas

Ragas is an open-source evaluation framework specifically designed for RAG (Retrieval-Augmented Generation) pipelines. It provides metrics for context precision, context recall, faithfulness, and answer relevancy, helping teams measure and improve the quality of their RAG systems. Ragas has become the standard evaluation toolkit for teams building production RAG applications.

What is Observability, Prompts & Evals?

Tools for monitoring LLM applications in production, managing and versioning prompts, and evaluating model outputs. Includes tracing, logging, cost tracking, prompt engineering platforms, automated evaluation frameworks, and human annotation workflows.

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