Top LLM Observability and Evaluation Platforms in 2026: Langfuse, LangSmith, Braintrust, Arize, and More Compared

LLM observability and evaluation platforms have become essential infrastructure for AI production, with the market growing to $2.69B in 2026 and expected to reach $9.26B by 2030. Platforms like Langfuse, LangSmith, Braintrust, and Arize offer deep tracing, evaluation, and monitoring to address unique LLM failure modes.