Promptfoo is a CLI-first, open-source tool for LLM evaluation and red teaming, with YAML-based tests that run locally and in CI. Braintrust is an AI evaluation and observability platform that integrates production tracing, evaluation, CI/CD quality gates, and continuous improvement into a single workflow. This article compares Promptfoo and Braintrust across interface, observability, security testing, release control, and pricing so buyers can decide which platform fits how their team builds, tests, and ships AI.
Promptfoo is an open-source CLI for teams that want to run LLM evaluation and red teaming locally and in CI, using YAML files stored alongside application code. Promptfoo fits developer-led workflows where prompts, assertions, and security tests remain in the repository and are reviewed like any other code change. Promptfoo is strongest when the team prioritizes terminal-based workflows and deep red teaming coverage.
Braintrust is an AI evaluation and observability platform for production teams that need evaluation connected to release control and production feedback. Production traces, eval datasets, scorers, CI/CD quality gates, playgrounds, and human review operate on the same data layer, so teams can use the same scoring logic during development, on pull requests, and on live traffic. Braintrust fits teams that ship AI products into production and continuously improve quality after release.
| Dimension | Braintrust | Promptfoo |
|---|---|---|
| Best for | Continuous evaluation across development, CI/CD, and production | CLI-first local eval and LLM security testing |
| Primary interface | Platform UI, bt CLI, and native SDKs | CLI, YAML configs, and local web viewer |
| Evaluation approach | 25+ autoevals scorers, custom code scorers, LLM-as-a-judge, human review, offline and online evals | YAML assertions with custom JavaScript and Python assertions |
| Trace-level scoring | ✅ Full traces across tool calls, retrieval, and multi-step agent workflows | ⚠️ Primarily output-level evaluation |
| Production observability | ✅ Live tracing, online scoring, and production logs in one system | ❌ No built-in production monitoring |
| Production-to-eval workflow | ✅ One-click trace to regression test | ❌ No production trace capture |
| CI/CD quality gates | ✅ Native GitHub Action blocks PR merges on thresholds | ⚠️ GitHub Action runs evals; merge blocking relies on custom scripting |
| Red teaming and security testing | ⚠️ Custom code scorers, adversarial datasets, and LLM-as-a-judge; no plugin library | ✅ 142 plugins spanning OWASP LLM Top 10, OWASP API, OWASP Agentic, NIST AI RMF, MITRE ATLAS, and EU AI Act presets |
| AI assistant | ✅ Loop builds scorers, generates datasets, surfaces failure patterns, and suggests prompt fixes | ❌ Not available |
| Prompt management | ✅ Playground tied to production traces, prompt slugs, and environments | ⚠️ YAML prompts versioned in git |
| Query performance at scale | ✅ Brainstore optimized for AI trace workloads | ⚠️ OSS self-host uses SQLite and is not recommended for production |
| Framework integrations | Native SDK integrations and OpenTelemetry support across major AI agent and testing frameworks | 60+ providers and OpenTelemetry support |
| Collaboration | ✅ Unlimited users across engineering, PM, and review at every tier | ⚠️ CLI-first workflow; centralized collaboration sits in Enterprise |
| Free tier | 1M trace spans, 10K scores, 1 GB processed data, 14-day retention, unlimited users, projects, datasets, playgrounds, and experiments | Open source CLI with 10K red team probes per month |
| Paid pricing | $249/mo, 5 GB processed data, 50K scores, unlimited trace spans, custom topics, charts, environments, and priority support | ⚠️ Enterprise only, custom pricing |
| Self-hosting | Enterprise hybrid and self-hosted deployment | Enterprise On-Prem |
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Promptfoo is the better choice when evaluation runs from the terminal and lives in the repository. The strongest cases are CLI-first development, open source control, and red teaming.
CLI-first development inside the existing toolchain: Promptfoo installs as a single binary, reads prompts and tests from promptfooconfig.yaml, and runs from one command. Engineers can run evals the same way they run unit tests, cache results locally, and commit the config alongside application code. The local web viewer supports review during development without sending data to a third party.
Open-source ownership and transparency: Promptfoo's open-source codebase and public GitHub repository allow teams to inspect how assertions and red-team probes are defined and generated. Security-sensitive or air-gapped environments often need evaluation logic that can be reviewed, modified, and deployed inside the organization's own infrastructure. Promptfoo fits that requirement more directly than a hosted proprietary platform.
LLM red teaming and security testing depth: Promptfoo provides broad red-teaming coverage for jailbreaks, prompt injection, PII exposure, data exfiltration, agentic tool misuse, and supply chain risks. Built-in presets align with frameworks such as OWASP, NIST AI RMF, MITRE ATLAS, and the EU AI Act, which reduces setup work for regulated teams. Dynamic attack generation and strategies such as crescendo, jailbreak, and multilingual injection extend coverage beyond static test cases.
Braintrust is the better choice when evaluation has to stay connected to live traffic, release control, and shared review across engineering, product, and operations.
Braintrust captures full traces across tool calls, retrieval steps, and multi-step agent workflows, then scores those traces with the same logic used during offline evals. Online scoring runs continuously on live traffic. Brainstore, Braintrust's purpose-built database for AI observability, stores and queries large volumes of trace data that continue to change as judges add scores and reviewers add annotations, which keeps search and analysis fast even as usage scales into the tens or hundreds of millions of traces per month. Promptfoo does not include a production observability layer.
When a user reports a bad response in Braintrust, the engineer opens the trace, clicks once, and the trace becomes an entry in the evaluation dataset that runs on every future deployment. The eval suite grows from real production failures, and each resolved incident strengthens coverage for the next release. Braintrust's shared data layer between tracing and evaluation removes the manual work that slows regression coverage. Promptfoo requires teams to recreate the incident manually as a YAML test case.
Braintrust ships the braintrustdata/eval-action GitHub Action, which runs evaluations on every pull request, posts a score summary as a PR comment, and blocks the merge when scores fall below defined thresholds. Braintrust treats merge blocking as a supported release-control workflow, so evaluation results can prevent a low-quality change from being released. Promptfoo supports CI, but pass-rate merge blocking requires custom scripting.
Braintrust ships the bt CLI for running evals, querying logs, and managing prompts from the terminal, so engineers who want terminal workflows can keep them. The Playground sits atop the same data, with side-by-side model comparisons, prompt slugs, environments, and human review workflows, allowing PMs and domain reviewers to work on the same traces that engineers are debugging. Unlimited users across all plan tiers keep collaboration open company-wide. Promptfoo's CLI-first and YAML-first model works well for engineers, but PMs and reviewers require the Enterprise tier to get centralized collaboration, team management, and audit logs.
Loop generates scorers from natural-language descriptions, pulls datasets from production logs, identifies failure patterns across traces, and suggests prompt fixes grounded in the results. A custom scorer that would normally take a senior engineer an afternoon to write can ship in minutes with Loop. Promptfoo does not include an equivalent built-in AI assistant.
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Braintrust and Promptfoo differ in both pricing structure and production readiness.
Promptfoo's Community plan is free and includes up to 10,000 red team probes per month. Promptfoo does not publish a starting Enterprise price, so teams planning a production deployment need a sales conversation before they can budget with confidence. Promptfoo's official self-hosting documentation states that the open-source self-hosted app is not recommended for production use cases because it uses a local SQLite database, does not support horizontal scaling, and is intended for individual or experimental use.
Braintrust's free Starter plan includes 1M trace spans, 10,000 scores, 1 GB of processed data, and unlimited users, which gives teams room to evaluate the platform on real workloads before upgrading. Braintrust Pro costs $249 per month and includes 5 GB of processed data, 50,000 scores, 30-day retention, unlimited trace spans, and unlimited users. See Braintrust pricing here.
Promptfoo costs less when the workflow stays local, and the main requirement is open source red teaming. Braintrust becomes easier to budget once the workflow includes production observability, shared team access, and continuous evaluation, because the paid plan is public, the included usage is clear, and production deployment does not depend on custom Enterprise pricing.
Pick Promptfoo when the team works primarily in a terminal, keeps evaluation logic in YAML next to the application code, and treats LLM red teaming as the primary requirement. Promptfoo fits security-focused workflows where evals run locally or in CI, and the team needs broad coverage across frameworks such as OWASP, NIST, or MITRE ATLAS.
Pick Braintrust when evaluation needs to continue from development into CI/CD enforcement, production monitoring, and ongoing improvement. Braintrust keeps production traces, evals, human review, and release controls in the same workflow, so teams can catch regressions before release and turn production failures into reusable regression tests.
Airtable, Vercel, Stripe, Zapier, and Instacart all run Braintrust in production. Notion's AI team went from triaging 3 issues per day to 30 after adopting Braintrust's eval workflow. The Braintrust Starter tier includes enough capacity to build evaluation coverage against real production traffic before committing to a paid plan. Start free with Braintrust →
Braintrust is the better choice for most production AI teams because it covers evaluation, observability, release control, and continuous improvement within a single system. Promptfoo is the better choice when the primary requirements are CLI-first evaluation and deep red teaming, but Braintrust covers the complete AI quality lifecycle once the application starts serving real users.
Promptfoo supports OpenTelemetry and runs locally or in CI, making it easy to run red-teaming and security tests in Promptfoo while tracing, evaluating, and monitoring production traffic in Braintrust. Production teams that need deep LLM security testing alongside continuous evaluation and observability usually run Braintrust as the primary platform and keep Promptfoo on the side for red team runs. Braintrust also supports custom-code scorers and LLM-as-a-judge configurations that cover many safety evaluations without requiring a second tool.
Braintrust is the best LLM evaluation platform for production AI teams because it keeps production tracing, evaluation, CI/CD quality gates, and ongoing improvement in one system. Teams that need eval results to catch regressions before release and turn real production failures into reusable regression tests will usually find Braintrust the better fit.
Promptfoo is free in its open-source form and includes 10,000 red team probes per month, but production use moves into custom Enterprise pricing with no public starting price. Braintrust Pro costs $249 per month flat and includes unlimited users and trace spans, 5 GB of processed data, and 50,000 scores. The free Starter tier also includes 1 million trace spans, 10,000 scores, and unlimited users. Promptfoo costs less for local evaluation and red teaming, while Braintrust is easier to budget once production observability, shared team access, and continuous scoring become part of the workflow.
For most evaluation workflows, yes. Braintrust covers evaluation, observability, CI/CD quality gates, prompt iteration, and production monitoring on a single platform. Teams whose main requirement is plugin-based red teaming across frameworks such as OWASP, NIST, or MITRE may still keep Promptfoo for security testing while running evaluation and release workflows in Braintrust.