HELM vs Promptfoo
HELM
crfm.stanford.eduPromptfoo
promptfoo.devSide by side
| Figure | HELM | Promptfoo |
|---|---|---|
| Price from | Free | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | Yes |
| Web | Yes | Yes |
| Windows | — | Yes |
| macOS | — | Yes |
| Linux | — | Yes |
| API | Yes | Yes |
| Self-hosted | Yes | Yes |
| Plans published | 1 | 3 |
| Spec score · LLM Evaluation Tools | 8.3 (#7) | 8.4 (#6) |
| Spec score · AI LLM Evaluation Tools | 8.4 (#12) | 8.4 (#13) |
| Founded | 2022 | 2024 |
| Installation | The project instructs users to install HELM from PyPI with `pip install crfm-helm`. | Installation is available through npm, npx, Homebrew, and a project dependency; npm and npx require Node.js 22.22.0 or newer. |
| License | The repository identifies HELM as open source and links to an Apache-2.0 license. | The open-source project is distributed under the MIT license. |
| Model providers | Models from providers including OpenAI, Anthropic, and Google are accessible through a unified interface. | Provider documentation covers OpenAI, Anthropic, Google, Vertex, HTTP, JavaScript, Python, Ruby, shell, OpenAI Agents, and other services. |
| Support | Users are directed to open GitHub issues for questions, which maintainers address when bandwidth is available. | Community support is provided through chat and GitHub issues, while Enterprise includes professional services and dedicated Slack support. |
Plans
In their own words
HELM
HELM is an open-source Python framework for evaluating foundation models, including large language and multimodal systems. It supplies standardized datasets and benchmarks such as MMLU-Pro, GPQA, IFEval, and WildBench, with a unified interface for models from providers including OpenAI, Anthropic, and Google. Evaluations can examine accuracy, efficiency, bias, and toxicity, and can include custom metrics, LLM-as-a-judge checks, safety evaluations, and human review workflows. Users can configure private checkpoints or model servers, run inference locally, or send requests to an API. A web interface displays individual prompts and responses, while leaderboards compare models and benchmarks across areas such as medicine, finance, multilinguality, and world knowledge. HELM can reproduce published evaluation results and documents commands for running benchmarks, summarizing results, and starting a local server. It is free, Apache-2.0 licensed, and entered maintenance mode on June 1, 2026.
Promptfoo
Promptfoo helps developers and enterprises evaluate prompts and test AI applications for security risks. It compares prompt outputs across multiple models in a web view. Red-team testing simulates users to look for prompt injections, jailbreaks, data leaks, business rule violations and insecure agent tool use. Its getting-started guide lists more than 60 providers, including OpenAI, Anthropic, Google and local models such as Ollama. Integrations include CI systems such as GitHub Actions, GitLab CI, Jenkins, Azure Pipelines, CircleCI and Bitbucket Pipelines, plus Splunk, Burp Suite, Google Sheets and MCP. Installation is available through npm, npx or Homebrew. Promptfoo requires Node.js 22.22.0 or newer and recommends Node.js 24 LTS. The free Community plan includes all LLM evaluation features and 10k red-team probes per month, and can run locally or be self-hosted. Enterprise includes managed cloud deployment; On-Premise runs on customer infrastructure. Promptfoo says it is based in San Francisco, is now part of OpenAI and remains open source.