RAG Evaluation Frameworks Compared: RAGAS vs TruLens vs DeepEval

LLMs are getting stronger every day, and building a RAG pipeline has never been easier. Knowing whether it actually works is not. Most teams ship a RAG system, see decent-looking answers, and call it done, until users hit hallucination, missing context, or irrelevant chunks. That's where evaluation frameworks come in. RAGAS, TruLens, and DeepEval are three of the most widely used tools for measuring RAG quality. In this article, I'll break down how each one works and when to reach for it. A RAG system has two moving parts: the retriever, which fetches context, and the generator, which writes the answer using that context. If either half…