Promptfoo

Promptfoo is an open-source CLI and library for systematically testing and securing LLM applications, used by hundreds of thousands of developers and by teams at OpenAI and Anthropic.

On the evaluation side, it lets developers define tests in simple declarative YAML configs to compare prompts, models, and RAG pipelines side by side, measuring quality and catching regressions as prompts or models change, and it integrates cleanly into CI/CD so AI behavior is checked on every change.

On the security side, Promptfoo provides automated red-teaming that generates thousands of context-aware adversarial tests simulating real attacks such as prompt injections, jailbreaks, data leaks, and business-rule violations, then delivers remediation guidance directly in pull requests.

It also offers guardrails for real-time protection, code scanning to detect LLM vulnerabilities in IDEs and CI/CD, and model security testing and monitoring. The workflow is organized as connect, attack, and fix, integrating with CI/CD pipelines, GitHub, GitLab, and popular agent frameworks.

It is aimed at developers and AppSec teams building production AI features who need both reliability and safety.

Pros include being free and open source with strong industry adoption, a simple declarative configuration model, and the rare combination of evaluation plus security red-teaming in one tool; cons are that getting meaningful results requires writing good test cases and assertions, and the most advanced enterprise and collaboration features sit in paid commercial plans.

Pricing changes often, so check the official site for current plans.

Promptfoo's core capabilities include Declarative YAML tests for prompts and models, Side-by-side comparison across RAG pipelines, Automated red-teaming with adversarial attacks, Guardrails for real-time runtime protection, CI/CD, GitHub, GitLab, and agent integrations and Remediation guidance delivered in pull requests.

Declarative YAML tests for prompts and models is built in, Side-by-side comparison across RAG pipelines is built in, Automated red-teaming with adversarial attacks is built in, Guardrails for real-time runtime protection is built in, so you get a rounded toolkit rather than a single trick.

Each feature is designed to take the manual effort out of the task and help you reach a usable result faster, which is what makes Promptfoo worth a place on your shortlist.

On the plus side, users consistently highlight Free and open source with strong adoption, Simple declarative configuration and Combines evaluation and security red-teaming as the reasons they keep using Promptfoo.

It isn't perfect, though — Useful results require well-written test cases and Advanced enterprise features need paid plans are the trade-offs people most often mention, so weigh those against your own priorities before you commit.

As with any AI tool, the output still benefits from a quick human review, but Promptfoo gets you most of the way there with far less effort.

Promptfoo runs on a freemium pricing model, so you can start for free and only pay once you outgrow the free tier — handy for testing it on a real task before spending anything.

AI-tool pricing changes often, so always check the current plans, seats and add-ons on the official site for the latest details before you buy. Who is Promptfoo for? It's best suited for test and red-team prompts, agents, and rag apps.

Whether you're a beginner trying this kind of AI tool for the first time or a professional who'll use it every day, it's a credible option to consider.

If you're still deciding, compare Promptfoo against the alternatives and the head-to-head comparisons linked below — looking at features, pricing and real user ratings side by side is the fastest way to find the right fit for your workflow and budget.