Jun 6, 2026AI Infrastructure
LangSmith vs Langfuse: LLM Evaluation and Tracing Platforms in 2026
You cannot improve what you cannot measure. That principle sounds obvious until you are actually trying to apply it to an LLM application, where the inputs are natural language, the outputs are probabilistic, and your evaluation methodology is still a work in progress. LangSmith vs Langfuse is a comparison that matters precisely because both tools take measurement seriously, but they do it in ways that reflect fundamentally different views of where your bottleneck actually is.