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LangChain vs LangWatch
LangChain is a developer library for building agents, while LangWatch provides a full testing and observability platform.
LangChainFramework for building LLM apps and agents
LangWatchThe harder your agents get, the more you need LangWatch.Which to pick
Pick LangChain if you want…
- End-to-end agent engineering platform
- LLM app framework
Pick LangWatch if you want…
- Simulation-based testing for complex agents
Side by side
- What it is
- LangChain:LangChain is an open platform for building, testing, deploying, monitoring, and governing LLM agents.
- LangWatch:LangWatch is an open-core platform for simulating, testing and monitoring multi-turn AI agents end-to-end.
- Best for
- LangChain:End-to-end agent engineering platform
- LangWatch:Simulation-based testing for complex agents
- Who it’s for
- LangChain:Developers and teams building AI agents and LLM-powered applications.
- LangWatch:AI engineers, product managers and teams building production AI agents.
- Pricing
- LangChain:Freemium
- LangWatch:Freemium
- Plans
- LangChain:Developer $0 per seat per month · Plus $39 per seat per month
- LangWatch:Developer $0 · Growth $34 per core-seat / month
- Open source
- LangChain:Yes, 147,359 GitHub stars
- LangWatch:Yes, 4,939 GitHub stars
- Works with
- LangChain:—
- LangWatch:LangGraph, CrewAI, Pydantic AI, OpenTelemetry, LiteLLM proxy
LangChain features
- Build agents fast. Start with proven patterns, customize harness, context, memory and model choice.
- Trace-based testing. Debug runs with step-by-step tracing and query complex traces instantly.
- Managed deployments. Deploy long-running agents with serverless or dedicated sandboxes and 30+ endpoints.
- Production monitoring. Online evals, dashboards and alerts track quality, cost, latency and errors.
- Feedback loop engine. Automatically detect issues, diagnose root causes and feed fixes back into evals.
- Governance controls. Enforce cost limits, data redaction and human approval via LLM Gateway.
LangWatch features
- Scenario-driven simulations. Write plain-language scenarios that generate multi-turn conversations for agents.
- Red-team adversarial testing. Run adversarial simulations to surface jailbreaks, policy breaks and unsafe tool calls.
- Judge agent evaluation. LLM or custom judges score whole conversations with reasoning and pass/fail verdicts.
- Observability & tracing. Full OpenTelemetry-compatible traces of every token, tool call, cost and latency.
- CI/CD integration. Run simulations and evaluations locally or in pipelines on pull requests.
- Voice agent testing. End-to-end voice simulations with latency metrics and noise/interruption injection.
LangChain vs LangWatch FAQ
Is LangChain or LangWatch free?+
LangChain has a free plan (Developer); paid plans start at $39/month per user (Plus). LangWatch has a free plan (Developer) and paid plans.
Is LangChain or LangWatch open source?+
Yes, both are open source: LangChain (langchain-ai/langchain on GitHub, MIT license) and LangWatch (langwatch/langwatch on GitHub, Apache-2.0 license).
On DevHunt
Based on each tool's website and DevHunt data. Details may change; check the official sites.