Best LLM for RAG answer synthesis in 2026: Opus 4.8 wins
We ran 4 models through 6 RAG-specific prompts testing faithfulness, citation accuracy, and I-don't-know honesty. Opus 4.8 takes 15 of 18 head-to-heads.
Tag · rag
We ran 4 models through 6 RAG-specific prompts testing faithfulness, citation accuracy, and I-don't-know honesty. Opus 4.8 takes 15 of 18 head-to-heads.
RAG has 3 moving parts: ingestion, retrieval, and generation. Here's what each does, when RAG beats fine-tuning, and when to skip it entirely.