LangSmith
Debug, test, and monitor LLM applications and agents in production with LangChain's observability platform, billed by trace volume and seats.
The verdict on LangSmith: Teams building production LLM apps on LangChain who need full trace visibility into every call LangSmith's value is tightly coupled to LangChain: if your production LLM application is built on LangChain, the native tracing depth and evaluation dataset workflow are among the most mature in the category, and there's no good reason to use a different observability tool. Pricing: Free (5K traces) / $39/seat/mo Plus / Enterprise custom. Last reviewed: August 2026.
Best For
Teams building production LLM apps on LangChain who need full trace visibility into every call
Standout Feature
Native LangChain integration gives trace depth that framework-agnostic tools simply can't match
TL;DR
The obvious choice if you're already on LangChain, less useful if your stack isn't built on it.
Alternatives
Overview
LangSmith is the observability and evaluation platform built by the LangChain team for teams building production LLM applications, it logs every LLM call with full trace context, lets you define evaluation datasets and run automated quality checks, and provides a debugging interface that shows exactly where a chain went wrong. Where Langfuse is framework-agnostic, LangSmith has the tightest integration with LangChain and LangGraph, making it the default choice for teams already in the LangChain ecosystem. The dataset and evaluation workflow is particularly strong for teams that run regular regression testing on their chains.
Our Take
If your stack isn't built on LangChain, framework-agnostic alternatives like Helicone or Braintrust cover the same ground without the coupling. The free tier hits its 5,000-trace limit quickly in production, so active applications almost always end up on a paid seat. The honest guidance is simple: LangChain stack, use LangSmith; everything else, don't.
Key Features
- Full LLM call tracing
- LangChain native integration
- Evaluation datasets
- Automated regression testing
- Prompt playground
- Team collaboration
- • Native LangChain integration provides trace depth that third-party tools can't match
- • Evaluation dataset workflow is among the most mature in the LLM observability category
- • Playground lets you test chains interactively before deploying changes
- • Less useful for non-LangChain stacks compared to framework-agnostic alternatives
- • Free tier trace limits hit quickly in production
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Workflows Using This Tool
Step-by-step playbooks that put LangSmith to work.