Langfuse
8.2#1 in prompting toolFrom $29 a monthFree planWebAPILinuxSelf-hosted
VisitLangfuse vs Respan (formerly Keywords AI)
Respan (formerly Keywords AI)
6.7#21 in ai agent observability toolsFrom $199 a yearFree planWebAPISelf-hosted
VisitWhat both publish
| Fact | Langfuse | Respan (formerly Keywords AI) |
|---|---|---|
| Evaluations | Evaluation supports LLM-as-a-Judge, heuristic or code evaluators, human review, annotation queues, and scoring of production data or experiments. | Evaluators can combine LLM judges, deterministic code checks, and human review, and can score sampled production traffic. |
| Integrations | Langfuse lists more than 100 integrations spanning OpenTelemetry, Python and TypeScript, model providers, agent frameworks, gateways, and developer tools. | The integrations directory lists 171 integrations, including OpenTelemetry, LangChain, OpenAI, Anthropic, AWS Bedrock, Slack, and PostHog. |
| Product | Langfuse is an open-source AI engineering platform that helps teams collaboratively debug, analyze, and iterate on AI agent applications. | Respan describes itself as an AI gateway with built-in observability, evaluations, and security testing. |
Langfuse plans
- HobbyFree
- Core$29 a month
- Pro$199 a month
- Teams Add-on$300 a month
- Enterprise$2,499 a month
Respan (formerly Keywords AI) plans
- FreeFree
- Team$199 a year
- EnterprisePriced on request
Pick Langfuse if…
Langfuse suits teams building AI agent applications that need tracing, prompt management, and evaluation tools. It also supports teams that want to self-host the core on their own infrastructure.
Pick Respan (formerly Keywords AI) if…
Respan suits startup and enterprise teams that need to trace AI workflows, assess agent behavior, or monitor quality in production. Its listed self-hosted deployment and enterprise security options may suit teams with those requirements.