# Promptfoo

Hacker Approved page: https://hackerapproved.com/p/promptfoo/

8 people recommended Promptfoo in Hacker News comments, 1 had mixed feelings and 2 criticized it, November 2025 to October 2026. It was recommended in 6 of 12 months, in 9 threads. It does not meet the Hacker Approved badge rule.

**Verdict:** Open-source tool for testing prompts and model outputs with test cases run against any model. One critic is unhappy and finds it not worth investing in, given how fast things move.

Summary written by Claude from 12 comments. It was written before the November 2026 recount, and 10 of those comments still count.

## Why people recommend it

- Best open-source tool for evals (2 comments in the sample): "There are tools like promptfoo designed for this." ([source](https://news.ycombinator.com/item?id=49301347)) "You've built an industry standard with Promptfoo." ([source](https://news.ycombinator.com/item?id=47313441))
- Tests model outputs well (1 comment in the sample): "my experience with Promptfoo is great at testing model outputs" ([source](https://news.ycombinator.com/item?id=47323572))
- Evaluates new models and prompt changes (1 comment in the sample): "These help when evaluating new models/versions and when modifying the system prompt to guide the model." ([source](https://news.ycombinator.com/item?id=47912382))

## The badge

A product earns the Hacker Approved badge when at least 10 people recommend it, recommenders outnumber critics at least 2 to 1 (mixed feelings count toward neither side), it was recommended in at least 4 of the 12 months and in at least 5 different threads, and no single thread supplies more than half of the people who recommend it. Health and money products are never badged.

## Cite as

Hacker Approved, "Promptfoo", https://hackerapproved.com/p/promptfoo/ (8 recommend, 1 mixed, 2 criticize; Hacker News comments, November 2025 to October 2026).

Counts updated 2 Nov 2026, with data through October 31, 2026.