LangSmith vs MLflow Tracing
LangSmith
langchain.comMLflow Tracing
mlflow.orgSide by side
| Figure | LangSmith | MLflow Tracing |
|---|---|---|
| Price from | $39/mo | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | Yes |
| Web | Yes | Yes |
| Windows | Yes | — |
| macOS | Yes | — |
| Linux | Yes | Yes |
| API | Yes | Yes |
| Self-hosted | Yes | Yes |
| Plans published | 3 | 1 |
| Spec score · AI Agent Observability Tools | 9.1 (#4) | 8.4 (#10) |
| Spec score · AI LLM Observability Tools | 9.1 (#3) | 8.4 (#11) |
| Documentation | LangChain publishes reference documentation, integration guides, deployment instructions, a CLI guide and a REST API reference. | MLflow documentation has separate sections for LLM and agent development, tracing, and evaluation, and for traditional machine-learning workflows. |
| Evaluation | Evaluation supports offline datasets, online production evaluations, human annotation queues and side-by-side experiment comparison. | MLflow connects trace inspection with evaluation results to help assess application quality. |
| Human feedback | Annotation queues let teams assign runs to subject-matter experts and use feedback to calibrate evaluations, improve prompts, or augment datasets. | Users can attach feedback to traces with metadata such as the user and timestamp. |
| Integrations | Documented integrations cover OpenAI, Anthropic, Bedrock, Gemini, Mistral, LiteLLM, OpenTelemetry, CrewAI, Vercel AI SDK, PydanticAI, AutoGen and many other frameworks and providers. | The integrations directory organizes automatic tracing support across frameworks, coding agents, and model providers. |
| Purpose | LangSmith is a commercial agent engineering platform for building, testing, deploying, monitoring, and improving AI agents. | MLflow Tracing captures inputs, outputs, and metadata from each step of LLM application and agent requests to help diagnose bugs and unexpected behavior. |
| Rating on G2 | 4.4 out of 5 from 78 reviews. | No product rating or review count for MLflow Tracing is stated on the opened G2 MLflow marketplace page. |
| Self-hosting | Enterprise customers can run LangSmith self-hosted or hybrid on Kubernetes in AWS, Google Cloud or Azure. | The repository's setup instructions show starting an MLflow server locally and connecting tracing to it. |
| What it does | LangSmith is LangChain's framework-agnostic platform for observing, evaluating and deploying AI agents. | MLflow Tracing records inputs, outputs, and metadata for intermediate steps in LLM applications and AI agents so teams can inspect behavior and investigate issues. |
Plans
In their own words
LangSmith
LangSmith is a commercial agent-engineering platform for building, evaluating, deploying, monitoring, and improving AI agents. It supports offline evaluations on curated datasets and real-time scoring of production interactions. Evaluation methods include human review, heuristic checks, LLM-as-judge evaluators, pairwise comparisons, and custom Python or TypeScript evaluators. Annotation queues route runs to subject-matter experts for feedback that can calibrate evaluations, improve prompts, or augment datasets. The Playground compares prompt versions or model providers, and LangSmith chat can auto-improve prompts. Observability includes agent and retrieval tracing, token and general cost tracking, trajectory monitoring, online evaluations, and webhook or PagerDuty alerts. Traces can arrive through SDKs or an API from LangGraph, custom Python, or other stacks; SDKs are listed for Python, TypeScript, Go, and Java. Hosting ranges from cloud to hybrid and self-hosted Enterprise options. The Developer plan costs nothing, Plus costs $39 a month, and Enterprise pricing is custom.
MLflow Tracing
MLflow Tracing has no write-up on Specifiction yet; its figures are above.