Langfuse vs Promptfoo
Side-by-side comparison of features, pricing, and ratings
At a glance
| Dimension | Langfuse | Promptfoo |
|---|---|---|
| Best for | Teams running production LLM applications needing observability, prompt management, and eval in one platform. | Engineering teams requiring lightweight, CI-integrated prompt testing and red-teaming with reproducible offline evals. |
| Pricing | Freemium: free self-hosted (MIT), cloud Hobby (50k events/mo free), Pro ($59/mo), Team ($499/mo). | Freemium: free open-source CLI (MIT), Enterprise (contact sales for cloud dashboard and managed red-teaming). |
| Setup complexity | Easy: wrap LLM calls with a decorator; self-host requires Docker Compose. Full platform in minutes. | Lightweight: install via npm/pip, define YAML test configs, run CLI. No server needed. |
| Strongest differentiator | Unified observability + prompt management + eval in one open-source stack with production tracing. | Developer-first CI-native eval framework with comprehensive assertions and built-in red-teaming. |
Promptfoo vs Langfuse addresses two complementary needs: Langfuse is the better choice for teams that need production observability, tracing, prompt versioning, and eval in one integrated platform — especially for debugging agent behavior and monitoring cost/latency. Promptfoo wins for engineering teams that prioritize lightweight, CI-integrated offline eval and red-teaming with a scriptable CLI. Choose Langfuse if you need a holistic observability platform; choose Promptfoo if your primary workflow is automated prompt testing and security scanning in a CI pipeline.
Open-source LLM observability platform — traces, evals, prompts, datasets for production agents.
Visit WebsiteDeveloper-first framework for testing and evaluating LLM prompts, agents, and AI security at scale.
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Core capabilities: Langfuse vs Promptfoo
Langfuse is an observability-first platform that captures structured traces of every LLM call — inputs, outputs, tokens, cost, latency — and organizes them into sessions, user views, and dashboards. It includes prompt management with versioning, rollback, and deployment, plus built-in evaluation via LLM-as-judge, user feedback, and datasets for regression testing. Promptfoo is a developer-focused evaluation framework that runs offline: you define prompts and test cases in YAML/TS, run parallel assertions across providers, and get diffable reports for CI. Its assertion library is extensive: equality, regex, semantic similarity, LLM-as-judge, classifier, factual consistency, and latency budgets. Both support custom evaluators, but Langfuse integrates evaluation directly with production traces, while Promptfoo is designed for repeatable offline testing. Langfuse wins for production observability; Promptfoo wins for offline CI-grade evaluation.
AI/model approach: Langfuse vs Promptfoo
Langfuse is provider-agnostic with 80+ integrations including OpenAI, Anthropic, Gemini, Bedrock, Mistral, vLLM, and major frameworks. It captures traces automatically when using LangChain, LlamaIndex, LiteLLM, or the OpenAI SDK. Prompts and evals can use any model, and the playground allows live testing on production inputs. Promptfoo also supports all major providers (OpenAI, Anthropic, Gemini, HuggingFace, OpenAI-compatible) and custom HTTP endpoints. Its parallel execution lets you compare models side by side on the same test cases. Tie on provider coverage; Langfuse has deeper framework integration for tracing, Promptfoo has more flexible multi-model comparison in evals.
Integrations & ecosystem
Langfuse integrates deeply with LangChain, LlamaIndex, Vercel AI SDK, LiteLLM, LangGraph, OpenAI Agents SDK, CrewAI, and AutoGen, capturing hierarchical agent structure automatically. It is OpenTelemetry compatible and self-hostable on Docker, Kubernetes, AWS, GCP, Azure. Promptfoo integrates primarily via CLI with GitHub Actions, GitLab CI, and Jenkins for CI/CD, plus major LLM providers. Its ecosystem is smaller but focused on dev workflows. Langfuse wins for ecosystem breadth and depth (80+ integrations vs Promptfoo's CI-focused set).
Performance & scale
Langfuse is built for production scale: Postgres + ClickHouse + Redis, supports sampling and custom retention. The Team plan offers unlimited events. Self-hosted allows full control over scaling. Promptfoo runs as a CLI tool — its performance is limited by local compute and API rate limits. For large test suites, parallel execution helps but no built-in distributed processing. Langfuse wins for high-volume production environments; Promptfoo is better for focused offline test suites.
Developer experience
Promptfoo is CLI-first: install via npm/pip, write YAML configs, run promptfoo eval, and get reports. Ideal for developers who want to version-control tests and integrate into CI. Langfuse provides a rich web dashboard, decorator-based integration, and playground. Its learning curve is slightly higher due to more features, but setup is straightforward. Promptfoo wins for simplicity and CI integration; Langfuse wins for feature-rich UI and debugging.
Security and compliance
Langfuse offers SOC2, ISO27001, and HIPAA compliance on Pro/Enterprise, plus SSO and audit logs. Self-hosting ensures data residency. Promptfoo's OSS version has no compliance certifications; the Enterprise tier provides managed red-teaming and a compliance dashboard. For red-teaming, Promptfoo offers adversarial generation and jailbreak detection out of the box, which Langfuse lacks. Promptfoo wins for red-teaming security; Langfuse wins for compliance/audit requirements.
Pricing compared
Langfuse pricing (2026)
Langfuse offers a self-hosted open-source tier (MIT) with unlimited events and all features. Managed cloud tiers: Hobby (free, 50k events/mo, 1 project), Pro ($59/mo, 100k events/mo, unlimited projects, evals, datasets), Team ($499/mo, unlimited events, SSO, priority support). Self-hosted is free but requires infrastructure. No hidden overage fees; events are counted per LLM call trace. Enterprise plans with regional data residency and audit logs are available.
Promptfoo pricing (2026)
Promptfoo is free and open-source (MIT) for the CLI and all core features including red-team basics. The Enterprise tier (contact sales) adds a cloud dashboard, team runs, managed red-teaming, and SSO. Pricing is not publicly disclosed beyond that. The free CLI is fully functional for individual developers and small teams. No usage limits on the OSS version.
Value-per-dollar: Langfuse vs Promptfoo
For teams that need production observability and tracing, Langfuse's free Hobby tier (50k events/mo) provides substantial value, and the self-hosted version is unlimited. Promptfoo's free CLI offers unlimited local evals, making it more cost-effective for teams that only need offline testing. Promptfoo wins for teams purely focused on eval in CI; Langfuse wins for teams needing an all-in-one observability platform with competitive managed pricing. For large-scale production use, Langfuse's Team plan ($499/mo) for unlimited events is cost-effective compared to building equivalent infrastructure. For enterprise red-teaming, Promptfoo's undisclosed Enterprise pricing may be higher than Langfuse's Pro/Team tiers.
Who should pick which
- Startup debugging production agent failuresPick: Langfuse
Langfuse's structured tracing and session views let you replay exact agent steps to find failures, with free Hobby tier for low volume.
- Mid-size team testing prompt changes in CIPick: Promptfoo
Promptfoo's YAML config, parallel assertions, and CI integration (GitHub Actions) provide automated regression testing per commit.
- AI security team red-teaming a new agentPick: Promptfoo
Promptfoo's built-in adversarial generation and 30 canonical jailbreak patterns are purpose-built for red-teaming workflows.
- SaaS company tracking per-user LLM costPick: Langfuse
Langfuse's user-level cost and token tracking in dashboards enables accurate billing for multi-tenant apps.
- Developer comparing GPT-4o vs Claude on custom testsPick: Promptfoo
Promptfoo's parallel multi-provider execution and diffable reports make side-by-side comparison simple and measurable.
Frequently Asked Questions
Is Langfuse free to use?
Yes, Langfuse offers a free Hobby tier (cloud) with 50k events per month, and a fully free self-hosted version under MIT license with no event limits.
Is Promptfoo free?
Yes, Promptfoo is open-source under MIT license and the CLI with all core features including red-team basics is completely free.
What integrations do Langfuse and Promptfoo support?
Langfuse integrates with 80+ tools including OpenAI, Anthropic, LangChain, LlamaIndex, LiteLLM, LangGraph, and more. Promptfoo integrates with major LLM providers (OpenAI, Anthropic, Gemini, HuggingFace) and CI systems (GitHub Actions, GitLab CI, Jenkins).
Can I self-host Langfuse or Promptfoo?
Yes, both are open-source (MIT). Langfuse can be self-hosted via Docker Compose, K8s, or cloud VMs. Promptfoo is a CLI tool, so it runs locally without a server.
Which tool is better for CI/CD pipelines?
Promptfoo is purpose-built for CI/CD with native GitHub Actions, GitLab CI, and Jenkins integrations. Langfuse has CI integration via its API but is less lightweight for CI.
Do Langfuse and Promptfoo support red-teaming or security testing?
Promptfoo includes built-in red-teaming with adversarial generation and jailbreak detection. Langfuse does not have native red-teaming features but provides compliance (SOC2, HIPAA) on paid tiers.
How do I migrate from Langfuse to Promptfoo?
Migration involves moving your test definitions to Promptfoo's YAML/TS format and pointing evaluations to Promptfoo's CLI. No direct import tool exists; manual conversion of datasets is needed.
Which tool has a lower learning curve?
Promptfoo has a lower learning curve for developers familiar with CLI and YAML — install and run. Langfuse requires integrating a decorator but offers a rich UI for debugging.
Can I use Langfuse for evaluation only?
Yes, Langfuse provides LLM-as-judge evals, datasets, and regression testing, but it is designed as a full observability platform, not just eval.
Which tool is better for compliance-heavy industries?
Langfuse offers SOC2, ISO27001, and HIPAA compliance on Pro/Enterprise, plus self-hosting for data residency. Promptfoo lacks compliance certifications unless Enterprise is purchased.
Last reviewed: May 12, 2026