langwatch vs promptfoo
LLM operations and testing tools compared
langwatch and promptfoo both help teams test LLM applications. langwatch combines testing with production observability, gateway, and governance capabilities, while promptfoo focuses on repeatable evaluations and security testing through a CLI and library.
langwatch: Test and Monitor LLM Applications and AI Agents
LangWatch helps teams evaluate, test, and monitor LLM applications and AI agents in production. It combines observability, simulation testing, prompt management, an AI gateway, and governance, with cloud and self-hosted options.
promptfoo: Evaluate and Red-Team LLM Apps
Promptfoo is a TypeScript CLI and library for evaluating and red-teaming LLM-based apps. Compare prompts and models, scan for vulnerabilities, and run checks in CI/CD, with evaluations performed locally.
| langwatch | promptfoo | |
|---|---|---|
| Language | TypeScript | TypeScript |
| License | Apache-2.0 | MIT |
| Stars | 4.9k | 26.4k |
| Forks | 405 | 2.6k |
| Last analyzed | Oct 3, 2026 | Oct 24, 2026 |
Key differences
- langwatch covers observability, simulation testing, prompt management, an AI gateway, and governance; promptfoo centers on prompt and model evaluations and security checks.
- langwatch supports monitoring after deployment and organizational AI governance; promptfoo emphasizes repeatable tests in local development and CI/CD.
- langwatch offers cloud and self-hosted options; promptfoo provides a CLI and Node.js library, with Docker and Helm also supported.
- langwatch is licensed under Apache-2.0, with enterprise modules requiring a commercial license for production use; promptfoo is MIT-licensed.
- Both are written in TypeScript, while promptfoo declares Node.js 22.22.0 or newer and langwatch notes that self-hosting requires Node.js.
- promptfoo has 25.9k stars and 2.5k forks, compared with langwatch at 4.9k stars and 405 forks.
Choose langwatch if you…
- need production observability alongside agent simulation testing and evaluation.
- want a shared AI gateway with provider routing, virtual keys, and usage budgets.
- need governance workflows or visibility into coding-agent sessions and costs.
Choose promptfoo if you…
- want a CLI or Node.js library for repeatable prompt and model evaluations.
- need to compare model outputs and add regression checks to CI/CD.
- want to red-team LLM applications or scan code for LLM-related security and compliance issues.
Compare the numbers side by side, or add more projects
This comparison is generated with AI from the OSRepos analyses of both projects. Always check each project's repository and documentation before choosing.