Braintrust vs Respan (2026)
Updated February 28, 2026
vs
Overview
Rating
10.0 / 10
Rating
10.0 / 10
Best For
Teams that want structured evals, experiments, and datasets tied to production traces
Best For
Engineering and product teams running AI agents and LLM apps in production
Product Summary
Braintrust is an LLM evaluation and observability platform. Compare its evals, tracing, pricing, pros and cons, and alternatives.
Product Summary
Respan is LLM observability built into an AI router: nested traces for every agent run, evals on live production traffic, and a click from any score to its trace.
Starting Price
Free
Starting Price
$0
Free Trial
No
Free Trial
Yes
Free Version
Yes
Free Version
Yes
Website
Website
Key features
Core capabilities each platform advertises.
- Experiments comparing prompts and models
- Code-based and LLM-as-judge scorers
- Datasets built from production traces
- Production logging and tracing
- Nested traces for every LLM call, tool run, and agent turn
- Threads for multi-turn sessions
- Online evals on live production traffic
- LLM-judge, code, and human evaluators
- Datasets from production logs and experiments at scale
- Monitors with Slack, email, and webhook alerts
- Prompt versioning and deployment without code changes
Strengths and tradeoffs
What each tool does well, and the limitations to keep in mind.
Pros
- Unlimited users on every plan, including free
- Production traces, datasets, and experiments connect in one eval workflow
- Framework-agnostic SDKs across multiple languages
- Loop agent drafts scorers and datasets from your own data
Cons
- Processed data and scores bill separately, and both grow with eval volume
- 14-day retention on Starter and 30 days on Pro
- Gateway is in public preview with no SLA
- Self-hosting and custom data export are Enterprise only
Pros
- Every score links to the trace that produced it
- Evals run on live production traffic, not only on test sets
- Built into the router, so there's no separate gateway to integrate
- Monitors alert the moment a metric breaches
- Unlimited seats on the free plan
Cons
- The free plan retains data for 7 days
- The free plan includes 1k scores and 2 evaluators
- Ingestion throughput is metered per tier, starting at 412 logs per minute on Free
Braintrust or Respan — which should you choose?
Choose Braintrust if you wantChoose if you want
- Iterating on prompts with production data
- Running evaluations across model versions
- Building golden datasets from production traffic
- Human review of LLM outputs
Choose Respan if you wantChoose if you want
- Debugging agent failures down to the step that broke
- Catching quality regressions before users report them
- Turning production failures into test datasets
- Testing a prompt or model change against real cases before shipping
- Attributing LLM cost to each end customer
Compare Braintrust and Respan on your own traffic
10KFree traces/mo
1,000+Models
5 minSetup
Respan lets you trace LLM and agent calls across any model or framework, A/B test prompts on production traffic, and route requests across 1,000+ models through one gateway.
Try Respan free