langwatch vs windmill
Side-by-side comparison of two AI agent tools
langwatchfree
The platform for LLM evaluations and AI agent testing
windmillopen-source
Open-source developer platform to power your entire infra and turn scripts into webhooks, workflows and UIs. Fastest workflow engine (13x vs Airflow). Open-source alternative to Retool and Temporal.
Metrics
| langwatch | windmill | |
|---|---|---|
| Stars | 3.2k | 16.1k |
| Star velocity /mo | 80 | 80 |
| Commits (90d) | — | — |
| Releases (6m) | 10 | 10 |
| Overall score | 0.7020945474090241 | 0.7021117042325569 |
Pros
- +End-to-end agent simulation capabilities that test against full stack including tools, state, and user interactions with detailed failure analysis
- +Open standards approach with OpenTelemetry/OTLP support ensuring no vendor lock-in and framework-agnostic compatibility
- +Integrated workflow combining tracing, evaluation, prompt optimization, and monitoring in a single platform eliminating tool sprawl
- +Multi-language support with automatic UI generation from scripts in Python, TypeScript, Go, Bash, SQL, and more
- +High performance workflow engine claiming 13x faster execution than Airflow
- +Self-hostable open-source solution with AGPLv3 license providing full control and customization
Cons
- -As a specialized platform, may require learning curve and setup time for teams new to LLM evaluation workflows
- -Self-hosting option available but may require infrastructure management for teams preferring on-premises deployment
- -AGPLv3 license may restrict some commercial use cases and require careful compliance consideration
- -Being a comprehensive platform may introduce complexity for simple automation tasks
- -Self-hosting requires infrastructure management and maintenance overhead
Use Cases
- •Regression testing of AI agents before production deployment using realistic scenario simulations to identify breaking points
- •Production monitoring and observability of LLM-powered applications with detailed tracing and performance evaluation
- •Collaborative prompt engineering and optimization with domain expert annotations and version control integration
- •Building internal APIs and webhooks from existing scripts without additional infrastructure
- •Creating automated workflows for background jobs and data processing pipelines
- •Developing low-code internal applications with custom UIs for non-technical team members