Galileo AI vs Promptfoo: Observability, Prompts & Evals Comparison
Compare Galileo AI and Promptfoo side by side. Both are tools in the Observability, Prompts & Evals category.
Updated March 10, 2026
The short answer
Choose Galileo AI if generous free tier with 5,000 traces/month including Agent Reliability Platform.
Choose Promptfoo if completely free and open source (MIT license).
Want to compare Galileo AI and Promptfoo on your own traffic?
Respan lets you trace LLM and agent calls across any model or framework, A/B test prompts on production traffic, and route requests across 250+ models through one gateway. Free tier covers 10K traces per month. Setup in 5 minutes, no credit card.
Quick Comparison
| Category | Observability, Prompts & Evals | Observability, Prompts & Evals |
| Pricing | Freemium | — |
| Best For | AI teams who need to measure and improve the quality of their LLM outputs | — |
| Website | rungalileo.io | promptfoo.dev |
| Key Features |
| — |
| Use Cases |
| — |
Pros & Cons: Galileo AI vs Promptfoo
- +Generous free tier with 5,000 traces/month including Agent Reliability Platform
- +Recognized as Gartner Cool Vendor demonstrating industry validation
- +Research-backed metrics providing scientific rigor to evaluations
- +Real-time observability with automated drift detection and alerting
- +Established team of 142 employees providing solid support capacity
- −Limited public information about advanced features and capabilities
- −Pro plan pricing jumps from free to $100/month with potential gaps for small teams
- −Less community-driven compared to open-source alternatives like Langfuse
- +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
- −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
Pricing: Galileo AI vs Promptfoo
- · MIT license
- · Up to 10k probes/month
- · All core features
- · CLI and browser UI
- · Hosting costs
- · Database expenses
- · LLM API calls
- · Variable by usage
- · Advanced features
- · Higher probe limits
- · Priority support
- · Custom security
When to Choose Galileo AI vs Promptfoo
- Monitoring LLM output quality
- Detecting and preventing hallucinations
- Evaluating RAG pipeline accuracy
About Galileo AI
Galileo is an AI observability and evaluation platform designed to provide AI reliability for teams across the entire development lifecycle. The platform offers real-time observability that continuously evaluates systems in production, sending alerts if something goes wrong or if interactions drift from training data. Galileo provides powerful, research-backed metrics and evaluation-powered development workflows to help teams build, scale, monitor, and protect AI applications in real-time. The platform is recognized as a Gartner Cool Vendor and serves as a comprehensive solution for AI teams looking to ensure reliability and performance of their LLM applications. With the Agent Reliability Platform available as part of their free tier, Galileo makes advanced AI observability accessible to teams of all sizes. The platform emphasizes scalability, security, and premium support for enterprise customers while maintaining an approachable entry point through their generous free tier.
About 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.
What is Observability, Prompts & Evals?
Tools for monitoring LLM applications in production, managing and versioning prompts, and evaluating model outputs. Includes tracing, logging, cost tracking, prompt engineering platforms, automated evaluation frameworks, and human annotation workflows.
Browse all Observability, Prompts & Evalstools →Other Observability, Prompts & Evals Tools
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