Braintrust vs Langfuse: Which is Better in 2026?
Choosing between Braintrust and Langfuse? Both are popular llm observability & evals tools. Below we compare them on pricing, free tiers, features, and pros & cons so you can pick the right fit for your stack.
Quick verdict
Both are solid llm observability & evals options. Langfuse is cheaper to start, but the right choice depends on the specific features and integrations you need.
Braintrust vs Langfuse — Side by Side
| Braintrust | Langfuse | |
|---|---|---|
| Category | LLM Observability & Evals | LLM Observability & Evals |
| Pricing | Free · paid from $249/mo | Free · paid from $29/mo |
| Starting price | Free tier available | Free tier available |
| Free tier | ||
| Rating | 4.6 | 4.7 |
| Best for | LLM Observability & Evals — llm, evals | LLM Observability & Evals — llm, observability |
Pros & Cons
- Strongest eval and experiment workflow in the category
- Unlimited users, so PMs and domain experts can review outputs
- Generous startup program
- $0 to $249 is a steep step with nothing in between
- Closed source, and only Enterprise can self-host
- Short default retention on both self-serve plans
- Genuinely open source and self-hostable
- Unit pricing does not punish adding teammates
- Framework-agnostic: OpenTelemetry, LangChain, LlamaIndex, raw SDKs
- Prompt management and evals in the same tool as tracing
- Self-hosting at scale means running ClickHouse, Postgres and Redis
- Units add up quickly for agent traces with many spans
- Longer retention is gated behind the $199 plan
Key Features Compared
Braintrust
- 5 GB processed data (+$3/GB)
- 50k scores (+$1.50 / 1k)
- 30-day retention
- Unlimited users
- 6–12 months free for qualifying startups
Langfuse
- 100k units / month included
- $8 per extra 100k units
- Unlimited users
- 90 days of data access
Choose Braintrust if…
- You want a free tier to validate before paying.
- Strongest eval and experiment workflow in the category
- Unlimited users, so PMs and domain experts can review outputs
- Generous startup program
Choose Langfuse if…
- You want a free tier to validate before paying.
- Budget is tight — paid plans start lower ($29/mo vs $249/mo).
- Genuinely open source and self-hostable
- Unit pricing does not punish adding teammates
Frequently Asked Questions
Is Braintrust better than Langfuse?⌄
Both are solid llm observability & evals options. Langfuse is cheaper to start, but the right choice depends on the specific features and integrations you need.
What is the difference between Braintrust and Langfuse?⌄
Braintrust — Eval-first AI observability with unlimited users on every plan. It is priced on data processed and scores run, not seats. Langfuse — Open-source LLM tracing, evals and prompt management: MIT-licensed, self-hostable, and $29/month in the cloud with unlimited users. Both are llm observability & evals tools; the comparison table above breaks down pricing, free tiers, and what each is best for.
Braintrust vs Langfuse: which is cheaper?⌄
Braintrust pricing: Free · paid from $249/mo. Langfuse pricing: Free · paid from $29/mo. Confirm current pricing on each tool's official site, as plans change.
Which is rated higher, Braintrust or Langfuse?⌄
In our catalog, Braintrust rates 4.6 out of 5 and Langfuse rates 4.7 out of 5, so Langfuse has a slight edge on reviews.
See more options in our guide to the best llm observability & evals tools for startups.
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