LLM Evaluation
Measure and control your AI’s performance
Flexible &
risk-free pricing
Test your LLMs with instant output insights. Use custom metrics, built-in checks, and guardrails like PII and jailbreak detection while continuously tracking performance.
Test your LLMs with instant output insights. Use custom metrics, built-in checks, and guardrails like PII and jailbreak detection while continuously tracking performance.


Trusted by AI innovators & global enterprise
Trusted by AI innovators & global enterprise
Trusted by AI innovators & global enterprise

Nikhil Nagaraj
CTO - Struck
"LangWatch is helping us understand what users are asking and if the actual answer provided is correct. It's great to evaluate our RAG application with the evaluations setup and knowing what users like / dislike. Thanks so much for all the support"
Nikhil Nagaraj

Nikhil Nagaraj
CTO - Struck
"LangWatch is helping us understand what users are asking and if the actual answer provided is correct. It's great to evaluate our RAG application with the evaluations setup and knowing what users like / dislike. Thanks so much for all the support"
Nikhil Nagaraj

Nikhil Nagaraj
CTO - Struck
"LangWatch is helping us understand what users are asking and if the actual answer provided is correct. It's great to evaluate our RAG application with the evaluations setup and knowing what users like / dislike. Thanks so much for all the support"
Nikhil Nagaraj
AI evaluations, automated - from dev to production
Test your agents and prevent regressions

Run Realtime and Offline Evaluations
Integrate any model and start evaluating with live production data or offline datasets. Track metrics over time, debug regressions instantly, and ensure consistent performance from development to deployment.

Run Realtime and Offline Evaluations
Integrate any model and start evaluating with live production data or offline datasets. Track metrics over time, debug regressions instantly, and ensure consistent performance from development to deployment.

Run Realtime and Offline Evaluations
Integrate any model and start evaluating with live production data or offline datasets. Track metrics over time, debug regressions instantly, and ensure consistent performance from development to deployment.

Build your own Eval Framework
Use our flexible framework to define custom metrics, test logic, and success criteria tailored to your LLM, agent, or product requirements.

Build your own Eval Framework
Use our flexible framework to define custom metrics, test logic, and success criteria tailored to your LLM, agent, or product requirements.

Build your own Eval Framework
Use our flexible framework to define custom metrics, test logic, and success criteria tailored to your LLM, agent, or product requirements.

Custom Evaluators Tech & Non-Tech
The only platform where both developers and non-technical users can build custom evals. Define what “good” looks like from retrieval to reasoning, with code or no-code.

Custom Evaluators Tech & Non-Tech
The only platform where both developers and non-technical users can build custom evals. Define what “good” looks like from retrieval to reasoning, with code or no-code.

Custom Evaluators Tech & Non-Tech
The only platform where both developers and non-technical users can build custom evals. Define what “good” looks like from retrieval to reasoning, with code or no-code.

Safeguard your AI systems
Safeguard your AI with automated safety checks and customizable guardrails. Ensure reliable, compliant, and controlled model behavior at all times.

Safeguard your AI systems
Safeguard your AI with automated safety checks and customizable guardrails. Ensure reliable, compliant, and controlled model behavior at all times.

Safeguard your AI systems
Safeguard your AI with automated safety checks and customizable guardrails. Ensure reliable, compliant, and controlled model behavior at all times.
Evaluation Wizard - Built for tech and non-technical Users
Evaluation Wizard - Built for tech and non-technical Users
Enable anyone on your team, product, devs, QA, domain experts to define your quality framework and run evaluations with zero code
No-code interface
to build eval logic and workflows
Test new prompts or models
before they’re pushed to production
Collaborate across teams
with shared evaluations and result views



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import langwatch
evaluation = langwatch.evaluation.init("my-experiment")
for idx, row in evaluation.loop(df.iterrows()):
response = my_agent(row["question"])
evaluation.log("sample_metric", index=idx, score=0.95)
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import langwatch
evaluation = langwatch.evaluation.init("my-experiment")
for idx, row in evaluation.loop(df.iterrows()):
response = my_agent(row["question"])
evaluation.log("sample_metric", index=idx, score=0.95)
API-based or platform native -keep control where required
API-based or platform native -keep control where required
CI/CD Evaluation Pipelines
Run evaluations continuously as part of your deployment stack. Keep your own infrastructure and workflows — no changes required.
Evaluate Structured Outputs and Tool Calls
Support complex evaluation formats, from JSON and function calling to multi-tool agents. Understand how your models behave in real-world applications
Air-Gapped and Self-Hostable
Run everything locally or in your private cloud. No lock-in, no external dependency full control over your data, models, and eval flows.
From Evaluation to Optimization
Automatically tune prompts, selectors, and agents based on evaluation feedback.
Ship agents with confidence, not crossed fingers
Get up and running with LangWatch in as little as 5 minutes.
Ship agents with confidence, not crossed fingers
Get up and running with LangWatch in as little as 5 minutes.
Ship agents with confidence, not crossed fingers
Get up and running with LangWatch in as little as 5 minutes.
Platform
Integrations
Platform
Integrations
Platform
Integrations