Langfuse vs Promptfoo

Side-by-side comparison of two AI agent tools

Short answer

  • Langfuse is growing faster: +1,812 GitHub stars in the last 30 days vs +1,112 for Promptfoo.
  • Pick Langfuse for: open-source LLM engineering platform for observability, evaluation, prompt and dataset management. Pick Promptfoo for: open-source CLI and library for evaluating and red-teaming prompts, agents, RAG systems, and LLM apps.

From GitHub data refreshed daily.

Langfuseopen-source

Open-source LLM engineering platform for observability, evaluation, prompt and dataset management

Promptfooopen-source

Open-source CLI and library for evaluating and red-teaming prompts, agents, RAG systems, and LLM apps

Metrics

LangfusePromptfoo
Stars35.3k25.6k
Star velocity /mo1.8k1.1k
Commits (90d)2.0k913
Releases (6m)1010
Overall score0.90672926166320360.8742860723201702

Pros

  • +Open source with MIT license allowing full customization and transparency, plus active community support
  • +Comprehensive feature set combining observability, prompt management, evaluations, and datasets in one platform
  • +Extensive integrations with major LLM frameworks and tools including OpenTelemetry, LangChain, and OpenAI SDK
  • +Comprehensive testing suite covering both performance evaluation and security red teaming in a single tool
  • +Multi-provider support with easy comparison between OpenAI, Anthropic, Claude, Gemini, Llama and dozens of other models
  • +Strong CI/CD integration with automated pull request scanning and code review capabilities for production deployments

Cons

  • -May require significant setup and configuration for self-hosted deployments
  • -Could be overwhelming for simple use cases that only need basic LLM monitoring
  • -Self-hosting requires technical expertise and infrastructure resources
  • -Requires API keys and credits for multiple LLM providers, which can become expensive for extensive testing
  • -Command-line focused interface may have a learning curve for teams preferring GUI-based tools
  • -Limited to evaluation and testing - does not provide actual LLM application development capabilities

Use Cases

  • •Production LLM application monitoring to track performance, costs, and identify issues in real-time
  • •Prompt engineering and management for teams collaborating on optimizing model prompts and tracking versions
  • •LLM evaluation and testing to measure model performance across different datasets and use cases
  • •Automated testing and evaluation of prompt performance across different models before production deployment
  • •Security vulnerability scanning and red teaming of LLM applications to identify potential risks and compliance issues
  • •Systematic comparison of model performance and cost-effectiveness to optimize AI application architecture

FAQ

Which is more popular, Langfuse or Promptfoo?
Langfuse has more GitHub stars (35,301 vs 25,640).
Which is more actively developed, Langfuse or Promptfoo?
Langfuse had more commits in the last 90 days (2,007 vs 913).
Should I use Langfuse or Promptfoo?
Compare their capabilities, limitations and "best for" notes above. Both are open source, so trying each on a small task is the fastest way to decide.