What is LangWatch?
LangWatch is a platform for testing and evaluating large language model (LLM) agents, providing real‑time simulations and prompt‑management tools for developers and product teams.
It captures production traces, turns them into reusable evaluation cases, and runs batch or synthetic tests across multiple models and languages.
Engineers can version, compare, and deploy prompts and model changes with full audit trails, while product managers can review results through a UI without writing code.
The system integrates natively with OpenTelemetry, LangChain, LangGraph, and other frameworks, allowing seamless insertion into existing testing pipelines.
LangWatch details
- Company
- Reasoning Engine B.V.
- Jurisdiction
- Netherlands
- Built for
- Businesses and teams
- Stated compliance
- GDPR, ISO 27001
Compliance as stated in LangWatch's own published documentation.
LangWatch tech specs
- Works with
- OpenAI / GPT Anthropic / Claude Google / Gemini ElevenLabs
- Cloud
- AWS
- Integrations
- Slack Discord GitHub Twilio
LangWatch pricing
FreeThis tool is free to use, with no credit card required.
- Free trial
- 14 days
- Auto-renewal
- Yes
Verify on the official pricing page.
Get started freeLangWatch's key features
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Simulate multi-step agent behavior
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Self-hosted trace evaluations
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Real-time LLM observability
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Prompt and model versioning
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Automatic test suite execution
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Dataset conversion from traces
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Seamless OpenTelemetry integration
LangWatch use cases
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Validate a customer‑support LLM agent in real‑time by simulating user interactions, capturing audit trails, and integrating OpenTelemetry traces, all without code in the no‑code evaluation UI, before rolling out to the live platform.
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Conduct batch performance tests across multiple LLMs (e.g., GPT‑4, Claude) for a compliance‑heavy financial advisory bot, automatically recording prompt outcomes and audit trails to satisfy regulatory reporting.
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Integrate LangWatch into a CI/CD pipeline for a multi‑language virtual assistant built with LangChain, enabling instant simulation, prompt version control, and role‑based access to review changes before each deployment.
LangWatch user reviews
Based on 1 review, 100% of users recommend LangWatch, rated highly for quality results.
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Who is LangWatch for?
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Data analysts
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Software developers
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System administrators
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Technical writers
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Monitoring engineers
LangWatch FAQ
Is LangWatch free?
Yes. LangWatch is free to use and does not require a credit card.
Is LangWatch safe to use?
LangWatch states GDPR and ISO 27001 compliance in its own published documentation. LangWatch is operated by Reasoning Engine B.V., registered in Netherlands. It has a substantial audience that is independently measured month to month.
What are the best alternatives to LangWatch?
The closest alternatives to LangWatch are Keywords AI, Latitude, Openlit, liteLLM and Klu.ai. You can compare them side by side in the alternatives section further down this page.
What does LangWatch do with my data?
LangWatch states that customer content is not used to train its models. Its privacy policy states that personal data is not sold or shared for marketing purposes. Data may be shared with third-party service providers that help run the product.
Does LangWatch auto-renew or offer refunds?
LangWatch subscriptions renew automatically until you cancel.
Does LangWatch have an API?
Yes. LangWatch offers an API, so you can call it from your own applications instead of using the interface directly.
Who made LangWatch?
LangWatch is built and operated by Reasoning Engine B.V., a company registered in Netherlands.
Which AI models does LangWatch use?
LangWatch is built on OpenAI / GPT, Anthropic / Claude, Google / Gemini and ElevenLabs. Which models you can reach may depend on your plan.
What does LangWatch integrate with?
LangWatch connects with Slack, Discord, GitHub and Twilio.
Compliance, privacy and billing terms are as stated in each product's own published documentation and have not been independently verified by TopAI.tools.
