Key features
Core capabilities each platform advertises.
OpenObserve- Logs, metrics, traces, RUM, and session replay
- OpenTelemetry-native LLM tracing with token and cost tracking
- Online evaluations with LLM-judge or remote scorers
Data not available
Updated March 10, 2026
OpenObserve is an open-source observability platform for logs, metrics, traces, and LLM apps, priced per GB with no seat or host fees.
Promptfoo is an open-source tool for testing and evaluating LLM prompts. It lets developers define test cases, run them against multiple models, compare outputs side-by-side, and catch regressions before deployment. Supports custom scoring functions, red-teaming, and CI/CD integration for automated prompt testing.
Core capabilities each platform advertises.
OpenObserveWhat each tool does well, and the limitations to keep in mind.
OpenObservePros
Cons
Pros
Cons
Choose OpenObserve if you wantChoose if you want
Choose Promptfoo if you wantChoose if you want
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.
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