Braintrust vs Langfuse: Observability, Prompts & Evals Comparison
Compare Braintrust and Langfuse side by side. Both are tools in the Observability, Prompts & Evals category.
The short answer
Choose Braintrust if custom-built Brainstore database optimized for AI data with fast full-text search and low latency.
Choose Langfuse if fully open-source with MIT license and free for commercial use with no usage limits.
Want to compare Braintrust and Langfuse on your own traffic?
Respan lets you trace LLM and agent calls across any model or framework, A/B test prompts on production traffic, and route requests across 250+ models through one gateway. Free tier covers 10K traces per month. Setup in 5 minutes, no credit card.
Quick Comparison
| Category | Observability, Prompts & Evals | Observability, Prompts & Evals |
| Pricing | Freemium | Open Source |
| Best For | AI teams who need a unified platform for logging, evaluating, and improving LLM applications | Teams who want open-source LLM observability they can self-host and customize |
| Website | braintrust.dev | langfuse.com |
| Key Features |
|
|
| Use Cases |
|
|
Pros & Cons: Braintrust vs Langfuse
- +Custom-built Brainstore database optimized for AI data with fast full-text search and low latency
- +Framework agnostic with native SDKs for multiple languages and no vendor lock-in
- +Comprehensive security and compliance certifications including SOC 2 Type II, GDPR, and HIPAA
- +AI-assisted Loop Agent for automated optimization of prompts and evaluations
- +Strong backing with $80M Series B funding and customers including Vercel, Notion, Coursera, and Dropbox
- −Relatively new platform founded in 2022, less mature than some competitors
- −Pro plan at $249/month may be expensive for smaller teams or individual developers
- −Limited public information about advanced features and customization options
- +Fully open-source with MIT license and free for commercial use with no usage limits
- +Acquired by ClickHouse in January 2026, providing strong backing and future investment
- +Active development with strong community support and comprehensive documentation
- +Transparent pricing model based on units rather than complex metric calculations
- +Deep integrations with major frameworks like LangChain, OpenAI, and LlamaIndex
- −Recent acquisition by ClickHouse may lead to platform changes and strategic shifts
- −Smaller team of 7 employees may impact support capacity
- −Enterprise pricing at $3,450-$5,700/month can be expensive for mid-sized teams
When to Choose Braintrust vs Langfuse
- Iterating on prompts with real production data
- Running evaluations across model versions
- Building golden datasets from production traffic
- Self-hosted LLM monitoring
- Open-source tracing for AI applications
- Prompt versioning and management
About Braintrust
Braintrust is an AI observability and evaluation platform that helps teams build, monitor, and improve AI applications in production. The platform enables users to turn production traces into evaluations, compare prompts and models, and improve quality with every release. Built on a custom database called Brainstore designed specifically for AI data complexity, Braintrust provides real-time trace inspection, performance monitoring for latency, cost, and quality, along with automated alerts. The platform features Loop Agent for AI-assisted optimization of prompts, scorers, and datasets, and offers framework-agnostic native SDKs for Python, TypeScript, Go, Ruby, and C# with no vendor lock-in. Braintrust is SOC 2 Type II, GDPR, and HIPAA compliant with SSO/SAML integration and granular role-based access control.
About Langfuse
Langfuse is an open-source LLM engineering platform that provides comprehensive tools for traces, evaluations, prompt management, and metrics to debug and improve LLM applications. Founded in Berlin, Germany in 2022, Langfuse quickly became a leading platform in the LLM observability space. The platform features MIT-licensed open-source core with no usage limits for commercial use, making it highly accessible to teams of all sizes. Langfuse offers deep integration with popular frameworks including LangChain, OpenAI, LlamaIndex, and LiteLLM. The platform provides detailed tracing capabilities, evaluation tools, comprehensive prompt management, and rich metrics tracking. In January 2026, Langfuse was acquired by ClickHouse, Inc., marking a significant transatlantic venture exit and validating the platform's technology and market position. The acquisition demonstrates the value of Langfuse's approach to LLM observability, evaluations, and prompt management.
What is Observability, Prompts & Evals?
Tools for monitoring LLM applications in production, managing and versioning prompts, and evaluating model outputs. Includes tracing, logging, cost tracking, prompt engineering platforms, automated evaluation frameworks, and human annotation workflows.
Browse all Observability, Prompts & Evalstools →Other Observability, Prompts & Evals Tools
More Observability, Prompts & Evals Comparisons
Run Observability, Prompts & Evals in production with Respan
One platform for routing, observability, tracing, and evals across every LLM provider.