Promptfoo — Observability, Prompts & Evals Platform
Observability, Prompts & EvalsLayer 4What is Promptfoo?
Promptfoo is an open-source tool for testing prompts, agents, and RAGs, with AI red teaming, pentesting, and vulnerability scanning for LLMs. Built under MIT license, Promptfoo was originally developed for LLM apps serving over 10 million users in production. The platform compares performance across GPT, Claude, Gemini, Llama, and more with simple declarative configs supporting command line and CI/CD integration. The Community version includes up to 10,000 probes monthly at no charge, with infrastructure costs typically USD 50-500 monthly for hosting and LLM API calls. Developers praise Promptfoo for its speed, quality-of-life features like live reloads and caching, security features including red teaming, and budget-friendly open-source model. However, the CLI-focused approach creates friction for non-technical team members, and the platform lacks end-to-end observability, version control for prompts, and test management features needed for complex production agents.
Pros & Cons
Pros
- +Completely free and open source (MIT license)
- +Fast with quality features like live reloads and caching
- +Built-in red teaming and security vulnerability scanning
- +Trusted by large companies with strong community
Cons
- -CLI-focused creates friction for non-technical users
- -Limited observability for complex production agents
- -No version control for prompts, data, or metrics
- -Offline nature hits ceiling for production scale
Promptfoo Pricing
Free trial available
- ✓MIT license
- ✓Up to 10k probes/month
- ✓All core features
- ✓CLI and browser UI
- ✓Self-hosted
- ✓CI/CD integration
- ✓Hosting costs
- ✓Database expenses
- ✓LLM API calls
- ✓Variable by usage
- ✓Advanced features
- ✓Higher probe limits
- ✓Priority support
- ✓Custom security
- ✓SLA guarantees
Using Promptfoo with Respan
Integrate Promptfoo's open-source LLM testing with Respan to add comprehensive evaluation and red teaming to your AI workflows. Test prompts, agents, and RAGs against security threats and performance benchmarks. With Respan orchestrating Promptfoo alongside your AI services, ensure quality and security before production deployment.
- ✓Test prompts against 100+ LLMs with performance comparison
- ✓Red team for injection attacks, jailbreaks, and vulnerabilities
- ✓Integrate seamlessly with CI/CD pipelines
- ✓Start free with 10k probes monthly in Community edition
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Last verified: March 10, 2026