Promptfoo

Open-source framework for evaluating and securing large language models.

EstablishedOpen SourceLow lock-in

Pricing

Free tier

Flat rate

Adoption

Rising

License

Open Source

Data freshness

Verified · Jul 16, 2026

Overview

What is Promptfoo?

Promptfoo is an open-source tool designed to evaluate and secure large language models by testing prompts, models, agents, and RAG pipelines. It includes adversarial attacks like jailbreaks and prompt injection, making it essential for integrating security into CI/CD processes.

Key differentiator

Promptfoo stands out as an open-source tool specifically designed to evaluate and secure large language models through adversarial attacks, making it unique among general-purpose AI testing tools.

Capability profile

Capability Radar

Ease of StartEcosystemValueMaturityFlexibilityScale Ready

Honest assessment

Strengths & Weaknesses

↑ Strengths

Evaluates large language models and RAG pipelinesmedium

Includes adversarial attacks for security testingmedium

Integrates with CI/CD processesmedium

Open-source under MIT licensemedium

↓ Weaknesses

Steep learning curve for non-Python developershigh

API requires Python-specific patterns, TypeScript SDK is community-maintained

Frequent breaking changes between versionsmedium

v0.1 to v0.2 migration required rewriting chain definitions

Limited language support beyond Pythonhigh

Primary development and maintenance focus on Python, with limited official support for other languages

Small community and slow issue resolutionmedium

GitHub issues often take weeks to receive a response from maintainers

Fit analysis

Who is it for?

✓ Best for

Teams needing to evaluate large language models for security vulnerabilities

Organizations integrating AI into CI/CD processes who require robust testing frameworks

Developers looking to enhance their model's resilience against adversarial attacks

✕ Not a fit for

Projects that do not involve the evaluation or deployment of large language models

Teams without a need for continuous security testing in their development lifecycle

Cost structure

Pricing

Free Tier

Available

Open source — free to use

Starts at

$0

Model

Flat rate

Enterprise

None

Performance benchmarks

How Fast Is It?

Ecosystem

Relationships

Next step

Get Started with Promptfoo

Step-by-step setup guide with code examples and common gotchas.

View Setup Guide →