Helicone vs Promptfoo
Features, pricing and Editor Score side by side — to help you pick the right coding & development tool in 2026.
Quick verdict
On our Editor Score, Helicone and Promptfoo land almost level. Pick Helicone if you want request logging across every major LLM provider; choose Promptfoo for automated red teaming with application-specific attack generation. On pricing, each has a free or freemium plan, so cost isn't the deciding factor here.
Helicone vs Promptfoo at a Glance
| Pricing | Freemium | Freemium |
| Free tier | ||
| Best for | request logging across every major LLM provider | automated red teaming with application-specific attack generation |
Helicone
Helicone is open-source LLM observability and an AI gateway. It logs and analyses requests across OpenAI, Anthropic, Gemini, Mistral, Groq, Together and OpenRouter, with sessions, user-level tracking, a query language, prompt management, datasets, a playground, rate limits and alerts.
- Covers the failure everyone hits — being unable to reconstruct what an AI feature actually did
- Session view makes multi-call interactions debuggable rather than guessable
- Per-user cost attribution reveals a spend distribution that totals completely hide
- Gateway positioning is what makes caching, routing and rate limiting possible at all
- Gateway mode puts a new dependency in your request path, with latency and availability consequences
- No latency overhead figures are published for that gateway position
- The open-source licence is not stated on the pages we read
Promptfoo
Promptfoo generates custom attacks against your own AI applications to find vulnerabilities including prompt injections, jailbreaks, data leaks, business rule violations and insecure tool use. It covers red teaming, evaluations, code scanning, model security, guardrails and MCP, with an open-source core.
- Generates attacks for your specific application rather than checking a list
- Business rule violation testing addresses rules that exist only in a prompt
- Names insecure tool use, which is the risk that grows as agents can act
- Open source core makes a security tool inspectable rather than trusted
- Finds attacks it knows how to generate; novel techniques appear constantly
- Results describe the system as configured, and configurations change
- Cannot fix architecture — a dangerous permission needs removing, not filtering
Which Should You Choose?
Choose Helicone if…
- you want request logging across every major LLM provider
- a free or freemium plan is important
Choose Promptfoo if…
- you want automated red teaming with application-specific attack generation
- a free or freemium plan is important
Helicone vs Promptfoo: The Verdict
Your use case decides this one: Helicone leans into request logging across every major LLM provider, while Promptfoo is built for automated red teaming with application-specific attack generation. Weigh features and pricing for your workflow. Both have a free or freemium tier, so spin up each and keep the one that clicks.
Frequently Asked Questions
Is Helicone better than Promptfoo?
Neither is universally better — it depends on your budget and which features matter most. The side-by-side breakdown above shows where each one wins.
What is the difference between Helicone and Promptfoo?
Helicone (freemium) is best for request logging across every major LLM provider, while Promptfoo (freemium) is best for automated red teaming with application-specific attack generation. See the full feature and pricing comparison above.
Is Helicone or Promptfoo cheaper?
Both have paid plans — pricing depends on your usage tier. Open each tool's review for current prices, and watch for free trials.
Which is better for beginners, Helicone or Promptfoo?
Helicone is usually the easier starting point thanks to a lower barrier to entry. Beginners should favour a free tier and a simple interface over raw power.
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About the Authors
AI Tools Comparison Analyst
Olivia runs side-by-side comparisons and benchmarks, digging into pricing, features, and real-world performance so readers can choose between competing AI tools with confidence.
Senior AI Tools Reviewer
Daniel reviews AI tools the slow way — by actually using them on real projects. His reviews cover what works, what breaks, and who each tool is genuinely a good fit for.
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Last updated October 2026. Comparisons are ranked by our Editor Score (features, value and pricing, blended with verified user reviews where a tool has them) — see our methodology.