head to head · open source
headroom vs promptfoo
headroom has 78,773 GitHub stars, 6,155 forks, 643 open issues and last shipped yesterday. promptfoo has 26,809 stars, 2,648 forks, 651 open issues and last shipped yesterday. headroom leads on adoption by 194% (78,773 vs 26,809 stars). headroom is written in Python under Apache-2.0; promptfoo is written in TypeScript under MIT. headroom has attracted 8% as many forks as stars, promptfoo 10%. headroom was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (llm), so they are genuine substitutes rather than adjacent tools.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| headroom | promptfoo | |
|---|---|---|
| GitHub stars | ★ 79K | ★ 27K |
| License | Apache-2.0 | MIT |
| Written in | Python | TypeScript |
| Last push | 2026-11-04 | 2026-11-04 |
| Forks | ⑂ 6.2K | ⑂ 2.6K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick headroom if
- You weight community size — 79K stars and counting
- You want the Apache-2.0 license terms
- Your stack matches Python
- You value the larger contributor base for long-term maintenance
pick promptfoo if
- You want the promptfoo feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches TypeScript
- You evaluated both and promptfoo fits your workflow better
About headroom
Quickstart · Install · Proof · Agents · Docs · Discord · llms.txt AI agents / LLMs: read /llms.txt here, or fetch the live index · full docs blob . Headroom compresses everything your AI agent reads — tool outputs, logs, RAG chunks, files, and conversation history — before it reaches the LLM. Same answers, fraction of the tokens. Compression runs on your machine; no prompt or file content is sent anywhere to be compressed. 10,144 → 1,260 tokens. The same FATAL found. What it does Library — compress(messages) in Python or TypeScript, inline in any app. Proxy — headroom proxy port 8787 , zero code changes, any…
read the full headroom overview →
About promptfoo
Promptfoo: LLM evals & red teaming promptfoo is a CLI and library for evaluating and red teaming LLM apps. Stop the trial and error approach start shipping secure, reliable AI apps. Website · Getting Started · Red Teaming · Documentation · Discord Promptfoo is now part of OpenAI. Promptfoo remains open source and MIT licensed. Read the company update. Quick Start Requires Node.js =22.22.0 for npm and npx usage. Node.js 24 LTS is recommended; see the runtime support guide. Also available via brew install promptfoo and pip install promptfoo . You can also use npx promptfoo@latest to run any command without…
read the full promptfoo overview →
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Frequently asked questions
Is headroom or promptfoo more popular?
headroom has 78,773 GitHub stars and promptfoo has 26,809. headroom has the larger community by that measure.
Are headroom and promptfoo free?
Both are open source. headroom is licensed under Apache-2.0 and promptfoo under MIT. Neither carries a licence fee.
What is the difference between headroom and promptfoo?
headroom is written in Python and promptfoo in TypeScript. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, headroom or promptfoo?
Choose headroom if you want the larger community (78,773 stars) or its Apache-2.0 licence terms. Choose promptfoo if its feature set, stack or MIT licence fits better. Both are self-hostable.