Confident AI (DeepEval) vs LangSmith
Which should you use? A side-by-side look at what each one does, who it suits, what it costs, how hard it is to set up, and where each falls short.
AI tool · Freemium
The cloud platform behind DeepEval, an open-source framework for unit-testing LLM outputs with ready-made metrics.
AI tool · Freemium
LangChain's platform for tracing, evaluating and monitoring LLM apps, with a prompt hub and playground.
The short answer
Choose Confident AI (DeepEval) if you need…
- Pytest-style LLM tests
- RAG evaluation metrics
Choose LangSmith if you need…
- LangChain and LangGraph users
- Dataset-based evaluation
Side-by-side
| Confident AI (DeepEval) | LangSmith | |
|---|---|---|
| Type | Prompting · Evaluation & observability | Prompting · Evaluation & observability |
| Price | Freemium | Freemium |
| Platforms | Web, API, CLI | Web, API |
| Works with | LangChain, LlamaIndex | LangChain, OpenAI |
| Hands-on tested by us | Not yet | Not yet |
| Last checked | 2026-10-29 | 2026-10-29 |
What each one is
Confident AI (DeepEval)
The cloud platform behind DeepEval, an open-source framework for unit-testing LLM outputs with ready-made metrics. Easy to drop into Python test suites. LLM-judged metrics can be noisy, so calibrate them against human review.
LangSmith
LangChain's platform for tracing, evaluating and monitoring LLM apps, with a prompt hub and playground. Deep tooling, especially inside the LangChain ecosystem. Less compelling if you don't use LangChain.
Best for
Confident AI (DeepEval)
- Pytest-style LLM tests
- RAG evaluation metrics
LangSmith
- LangChain and LangGraph users
- Dataset-based evaluation
Strengths
Confident AI (DeepEval)
- Open-source DeepEval metrics
- Test datasets
- Regression reports
- Tracing
LangSmith
- Detailed run traces
- Datasets and evaluators
- Prompt hub and playground
- Production monitoring
Frequently asked questions
What is the difference between Confident AI (DeepEval) and LangSmith?
Confident AI (DeepEval): The cloud platform behind DeepEval, an open-source framework for unit-testing LLM outputs with ready-made metrics. LangSmith: LangChain's platform for tracing, evaluating and monitoring LLM apps, with a prompt hub and playground. Confident AI (DeepEval) suits pytest-style llm tests, while LangSmith suits langchain and langgraph users.
Are Confident AI (DeepEval) and LangSmith free?
Confident AI (DeepEval): Freemium. LangSmith: Freemium.
What are other alternatives to Confident AI (DeepEval) and LangSmith?
Other options people compare them with include Langfuse, Arize Phoenix, Opik, promptfoo, Braintrust.
Keep comparing
Built from our catalogue entries for both products: open-source details come from each project's README (AI-assisted, refreshed weekly) and GitHub data; AI-tool details are editorial. Spotted something wrong? Let us know from either product's page.