Comparison

Braintrust vs Langfuse: Open Source Agent Evals & Observability

Braintrust and Langfuse: Open Source Agent Evals & Observability both land on Depends.

Braintrust

Depends

Confidence: Medium

Buy if you ship AI agents in production and want tracing, evals, and regression checks in one well-funded platform.

Depends

Confidence: Low

Buy if you ship LLM apps to production and need tracing, prompt management, and evals in one place; skip if you don't build AI features.

Braintrust versus Langfuse: Open Source Agent Evals & Observability
Compare	Braintrust	Langfuse: Open Source Agent Evals & Observability
Verdict	Depends	Depends
Best for	Teams shipping LLM agents in production	Teams shipping LLM apps to production
Who it's not for	Pre-production or hobby projects . eval tooling is premature	Teams not building LLM-powered products
Privacy	Confirmed breach: May 2026 AWS incident exposed customer AI provider API keys; every customer was told to rotate credentials.^¹	No known public vulnerabilities found in the sources reviewed.¹⁰
Support quality	No credible support evidence found.	No support-quality evidence found
Public sentiment	Independent reviews of this specific product are sparse, and much online 'Braintrust' feedback actually targets a similarly named recruiting marketplace, so sentiment is murky.^⁴	No independent user reviews surfaced in reviewed sources; all claims are vendor-published adoption and feature statements.^⁹
Biggest gotcha	2026 AWS breach exposed customer AI provider API keys; all customers had to rotate credentials.^¹	Free tier caps at 50k observations/month; high-volume agents outgrow it fast, costs scale with volume^⁹