Best Alternatives to LangSmith and LangFuse
Top LangSmith competitors and why Vecta leads for accuracy-first RAG evaluation.
Best Alternatives to LangSmith and LangFuse
When it comes to building production-ready AI systems, evaluation is everything. LangSmith has long been the default for developers in the LangChain ecosystem, but as Retrieval-Augmented Generation (RAG) and accuracy-first AI systems become the industry standard, many teams are looking for more specialized alternatives.
In this guide, we’ll walk through the top LangSmith competitors, their strengths, and why Vecta is the leading choice for teams who care about accuracy, reliability, and trust in AI systems.
1. Vecta
What is Vecta?
Vecta is the evaluation platform purpose-built for RAG systems. Instead of generic tracing or surface-level metrics, Vecta goes deep into granular synthetic benchmarks that measure precision, recall, hallucinations, and reasoning performance across your pipelines.
Teams use Vecta to reduce hallucination rates by up to 50%, enforce accuracy SLAs, and continuously monitor production RAG agents for regressions.
Key Features
- 🧪 Synthetic Benchmarks – Automatically generate domain-specific test sets (multi-hop retrieval, edge cases, adversarial prompts).
- 📊 Granular Metrics – Precision, recall, F1 score, hallucination rate, latency, groundedness.
- 🧮 Human-in-the-Loop – Expert annotators (M.Sc.+) for critical QA pipelines.
- 🔄 Versioned Evaluations – Reproducible benchmarks for CI/CD workflows.
- 📂 Dataset Management – Synthetic + HITL datasets with versioning and backups.
- 🌐 Universal Compatibility – Works with OpenAI, Anthropic, Cohere, Pinecone, Weaviate, PostgreSQL, Cosmos DB, LangChain, LlamaIndex, and more.
- 🛡️ Enterprise-Grade Security – SOC 2, HIPAA, GDPR readiness; self-hostable for data sovereignty.
Who uses Vecta?
Vecta is trusted by AI teams across industries:
- Enterprises with compliance-critical AI (finance, healthcare, legal).
- Growth-stage startups building RAG-powered products.
- AI/ML research teams pushing the limits of groundedness.
How does Vecta compare to LangSmith?
| Feature | Vecta | LangSmith |
|---|---|---|
| Synthetic benchmarks | Auto-generated, domain-specific | Limited |
| Granular RAG metrics | Precision, recall, F1, hallucinations | Tracing + scorecards |
| Accuracy SLAs | Supported | Not available |
| Human-in-the-loop | Built-in, expert annotators | Limited |
| Dataset management | Multi-level, versioned | Basic |
| Observability | Accuracy-first, RAG-specific | General-purpose |
| Integrations | 20+ databases & LLMs, API-first | Lang ecosystem-focused |
Bottom line: Vecta is the only evaluation-first platform designed to make RAG systems trustworthy and production-ready.
2. Arize AI
Arize AI is an observability-first platform with strong roots in ML monitoring. With Phoenix, their OSS tracing library, they’ve extended into LLM evaluation.
- Strengths: Large-scale tracing, observability, self-hostable OSS.
- Weaknesses: Limited multi-turn and RAG-specific evals, restrictive free tier.
Best for large enterprises needing observability at scale, less ideal for teams who need accuracy-first RAG benchmarks.
3. Braintrust
Braintrust Data takes a more non-technical friendly approach, offering a playground UI for model/prompt testing.
- Strengths: No-code playground, collaborative testing.
- Weaknesses: Limited OSS adoption, fewer advanced eval features.
Best for PMs and non-technical teams, but limited for engineering-heavy orgs.
4. Langfuse
Langfuse is a 100% open-source alternative to LangSmith with tracing, prompt management, and basic evals.
- Strengths: OSS, great DX, wide adoption.
- Weaknesses: Limited synthetic evaluation and accuracy metrics.
Best for teams that need OSS-first observability, but not sufficient for mission-critical RAG accuracy guarantees.
5. Helicone
Helicone focuses on acting as an AI gateway for 100+ LLM providers while offering request-level observability.
- Strengths: Works across many LLM APIs, open-source, easy to set up.
- Weaknesses: Limited eval depth, observability focused on requests rather than RAG pipelines.
Best for startups juggling multiple LLM providers.
Honorable Mentions
- Galileo AI, Traceloop, Gentrace – Closed-source observability tools with limited community traction.
- Keywords AI – Popular in early-stage startup circles, but less feature-complete.
Why Vecta Leads the Pack
LangSmith popularized evaluation within the Lang ecosystem, but the future of AI isn’t just about tracing, it’s about trust and accuracy.
That’s where Vecta comes in. With synthetic benchmarks, granular RAG metrics, and production-grade monitoring, Vecta is the best LangSmith alternative for teams serious about building AI systems you can trust.
✅ Reduce hallucinations by 50% ✅ Enforce accuracy SLAs ✅ Ship production-ready AI twice as fast
👉 Start for free or book a demo today.