Braintrust vs Langfuse: which LLM evals + tracing platform should you ship in 2026?
Braintrust is the polished commercial evals platform with strong UX. Langfuse is the open-source observability + prompt-registry leader with self-host. Pick Braintrust for polish, Langfuse for OSS + self-host.
At a glance
| Dimension | Braintrust | Langfuse |
|---|---|---|
| Open source / self-host | Closed cloud | Open source + self-hostWIN |
| Evals UX | Polished, best in classWIN | Solid |
| Tracing depth | Strong | Strongest in OSSWIN |
| Prompt registry | First class | First class |
| LLM-as-judge ergonomics | Excellent — built-inWIN | Solid |
| Production sampling + grading | First class | First class |
| SDK coverage | Python + TypeScript | Python + TypeScript + Java + GoWIN |
| Pricing | Cloud subscription | Free OSS + paid cloudWIN |
Verdict
Braintrust is the right pick for teams that want the most polished evals + tracing experience and don't need self-host. Langfuse is the right pick for teams that want open source, self-host, broader SDK coverage, or a free-tier-friendly OSS path. Both are credible in 2026; pick by hosting preference and budget.
When to pick which
Pick Braintrust
Polished commercial UX, strong LLM-as-judge ergonomics, cloud-first.
Pick Langfuse
Open source, self-host, broader SDK, OSS-friendly stack.
FAQ
Braintrust or Langfuse in 2026?
Braintrust for polished cloud workflow; Langfuse for OSS + self-host.
Cheapest of the two?
Langfuse OSS is free; Langfuse cloud is competitive on price.
Best for prompt registry?
Both are competitive; pick based on which surface (evals vs tracing) is your primary use.
Last updated: 2026-06-01.