Langfuse
Open Source LLM Engineering Platform
LangSmith
Build and deploy LLM applications with confidence
Updated February 2026
| Langfuse | LangSmith | |
|---|---|---|
| Rating | 5.0★ | 4.8★ |
| Reviews | 41 | 19 |
| Pros | 18 | 16 |
| FactScore™ | 81.2 | 63 |
FactScore™ Comparison
FactScore™ weighs both quality (rating) and popularity (reviews) for a fairer ranking than stars alone.
Pros & Cons
Only in Langfuse — Pros
LLM observability Open source Detailed tracing Monitoring capabilities Cost-effective Easy to integrate Free tier SDK availability Seamless integration Debugging tools Fast iterations Insightful analytics Community engagement Detailed analytics Excellent UI Flexible architecture Open API Robust telemetryBoth tools — Pros
—Only in LangSmith — Pros
Monitoring AI model performance Chain sequence debugging Evals Annotation queues CI/CD integration Comprehensive visibility Datasets Easy to use Flexibility outside LangChain LangGraph Metadata filtering Python SDK Real-time analytics Time-saving Tracing tools VersioningOnly in Langfuse — Cons
—Both tools — Cons
—Only in LangSmith — Cons
Filters not persisted in URL UI issues with large datasetsDetails
| Langfuse | LangSmith | |
|---|---|---|
| Categories | AI Infrastructure Tools, AI Metrics and Evaluation | AI Infrastructure Tools, AI Metrics and Evaluation |
| Platforms | Web | Web |
| Became Popular | August 20, 2023 | N/A |
| Website | langfuse.com | www.langchain.com |
Who Should Pick Which?
Choose Langfuse if...
- LLM observability
- Open source
- Detailed tracing
Choose LangSmith if...
- Monitoring AI model performance
- Chain sequence debugging
- Evals
With a FactScore™ of 81.2 vs 63, Langfuse leads in community reception. Langfuse uniquely offers LLM observability and Open source, while LangSmith stands out for Monitoring AI model performance and Chain sequence debugging.
What Users Say
Langfuse
Without Langfuse, we would have been flying blind with our drafting agent. This platform is critical not just for measuring performance, but for understanding exactly what context gets pulled into ...
So excited to see Langfuse go live — we've been a happy user for 4 weeks now. Most detailed latency and analytics in the market. Highly recommend for anyone using complex chains or with user-f...
We’ve been unsung Langfuse for 2 months now. It’s easy to integrate and makes it simpler for us to monitor & debug LLM requests during development and beyond.
LangSmith
We started building Ting without LangSmith and we were flying blind. Diagnosing issues downstream felt like guesswork. Since bringing LangSmith in, we’ve been able to trace problems through the ent...
We absolutely could not build this product with LangSmith for traces, datasets, annotation queues, and evals. We've become big power users! I use to build AI apps before nice tracing tools like thi...
Promptius <3 Langchain + Langgraph + Langsmith, this combination has been instrumental in building Promptius in the past 5 months! The abstractions provided by Langchain and Langgraph make building...
Related Comparisons
Frequently Asked Questions
Which is better, Langfuse or LangSmith?
Based on FactScore™, Langfuse leads with a score of 81.2 vs 63. Langfuse has a higher rating of 5.0★ compared to 4.8★.
What are the pros of Langfuse compared to LangSmith?
Langfuse uniquely offers: LLM observability, Open source, Detailed tracing, Monitoring capabilities, Cost-effective.
What are the pros of LangSmith compared to Langfuse?
LangSmith uniquely offers: Monitoring AI model performance, Chain sequence debugging, Evals, Annotation queues, CI/CD integration.
Is Langfuse better rated than LangSmith?
Langfuse is rated 5.0★ from 41 reviews. LangSmith is rated 4.8★ from 19 reviews.
What is the FactScore™ of Langfuse and LangSmith?
FactScore™ weighs rating and review volume together. Langfuse scores 81.2 and LangSmith scores 63.
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