It's hard to imagine doing web research without using LLMs. Chatbots may be the first thing you turn to for questions like: What are the companies currently working on nuclear fusion and who invested in them? What is the performance gap between open and closed-weight models on the MMLU benchmark? Is there really a Tesla Model H?

So which LLMs, and which "Search", "Research", "Deep Search" or "Deep Research" branded products, are best? How good are their epistemics, compared to if you did the web research yourself?

Last month we (FutureSearch) published Deep Research Bench (DRB), a benchmark designed to evaluate LLMs agents on difficult web research tasks using frozen snapshots of the internet. In this post, we're going to share the non-obvious findings, suggestions and failure modes that we think might be useful to anyone who uses LLMs with web search enabled.