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Braintrust vs Langfuse
Quick verdict
Key difference: Langfuse is open-source while Braintrust is proprietary.
Side-by-side comparison from the Agent Observability Index: licensing, self-hosting, pricing model and integrations — no vendor copy, primary sources linked.
| Braintrust | Langfuse | |
|---|---|---|
| One-liner | Eval-first AI engineering platform with logging, datasets, an LLM proxy and a purpose-built trace database (Brainstore), aimed at production regression-catching. | Open-source (MIT) LLM engineering platform combining tracing, prompt management, evals and datasets, widely used as the default self-hosted observability stack. |
| Category | Evals & Testing | Observability & Tracing |
| OpenTelemetry-native | — | Yes |
| Open source | No | Yes |
| Self-hostable | Yes | Yes |
| Pricing model | freemium | freemium |
| Pricing notes | Free developer tier; usage-based paid plans; enterprise hybrid/self-hosted data plane | Free Hobby tier (50k units/mo); Core $29/mo, Pro $199/mo, unlimited users on paid tiers; MIT core fully self-hostable |
| Frameworks | openai-sdk, anthropic, langchain, vercel-ai | langchain, openai-sdk, llamaindex, litellm, opentelemetry, vercel-ai, haystack |
| GitHub stars | — | 29k |
| Maturity (GitHub signal) | — (no public repo) | 90/100 (Mature) |
| Funding / ownership | $36M Series A (a16z, 2024) + $80M Series B (ICONIQ, Feb 2026, ~$800M valuation) | YC W23; $4M seed (Lightspeed, La Famiglia) |
How to choose
- Choose Langfuse if open-source licensing or full data control is a hard requirement.
- Both link to primary pricing sources below — verify current tiers before committing; this market shifts monthly.
Sources: Braintrust · Langfuse
Frequently asked questions
Is Braintrust or Langfuse open source?
Braintrust: No. Langfuse: Yes.
Can Braintrust and Langfuse be self-hosted?
Braintrust: Yes. Langfuse: Yes.
Braintrust vs Langfuse: which should I choose?
Key difference: Langfuse is open-source while Braintrust is proprietary.