LangSmith

Debug, evaluate, and monitor production AI applications

4.7/5 Rating Freemium - Free Developer Plan Per seat pricing,Trace overage charges,Extended retention costs,Deployment usage fees Free Trial Available

Enterprise Technology Specs

Underlying Engine OpenAI, Claude, Gemini, Llama, Mistral, Azure OpenAI
Compliance & Security SOC2 Type II, GDPR
Data Privacy Trains on anonymized data
Deployment Time <5 minutes

Product Demo

The Deep Dive

LangSmith has become one of the most important tools in the AI development ecosystem because it solves a problem nearly every AI team eventually faces: understanding why an LLM application behaves the way it does.

Instead of treating AI systems like black boxes, LangSmith gives developers detailed traces showing prompts, tool calls, model outputs, agent decisions, and execution paths. This dramatically speeds up debugging and evaluation workflows.

Its biggest advantage is how tightly it connects development, testing, monitoring, and deployment into one platform. Teams can move from experimentation to production without constantly switching tools.

The downside is that costs can grow quickly as trace volume increases, especially for large-scale AI products. Teams wanting complete infrastructure ownership may also prefer open-source alternatives. Still, for organizations building serious AI applications with LangChain or LangGraph, LangSmith remains one of the most polished and capable platforms available.

Key Capabilities

LLM tracing
Agent observability
Prompt debugging
Online evaluations
Offline evaluations
Monitoring and alerting
Dataset management
Human feedback queues
Prompt playground
Agent deployment

Top Use Cases

  • Agent debugging
  • Prompt optimization
  • LLM monitoring
  • AI testing
  • Production observability
  • Human feedback collection
  • Evaluation pipelines
  • Agent deployment
Verified ROI & Case Study

“LangSmith is used across thousands of AI applications to accelerate debugging, improve evaluation workflows, and reduce production troubleshooting time through trace-level observability.”

Frequently Asked Questions

Is LangSmith free?

Yes. LangSmith offers a free Developer plan that includes one seat, up to 5,000 traces per month, evaluations, monitoring, prompt tools, and community support. Additional usage is billed separately based on trace volume.

What is LangSmith used for?

LangSmith helps developers debug, evaluate, monitor, and optimize AI applications. Teams use it to inspect prompts, track agent behavior, measure performance, and improve LLM reliability in production.

Does LangSmith only work with LangChain?

No. While LangSmith works best with LangChain and LangGraph, it can also monitor and evaluate applications built with other frameworks and custom AI stacks.

Can LangSmith monitor AI agents?

Yes. Agent observability is one of LangSmith's core strengths. Developers can inspect tool calls, reasoning chains, execution paths, failures, and intermediate outputs.

Does LangSmith support evaluations?

Yes. LangSmith includes both online and offline evaluation workflows. Teams can compare prompts, score outputs, collect human feedback, and benchmark model performance over time.