Deep research (an AI feature that gathers sources and writes a report)
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Deep research is an AI feature that reads many websites on its own and turns what it finds into a report with sources. It takes minutes to tens of minutes, but it does research that would take a person hours.
Deep research is a feature where you ask an AI something like "research this topic and write me a report", and the AI makes a research plan, reads dozens or hundreds of websites, and writes a report with its sources listed. The name spread after OpenAI added it to ChatGPT in February 2025, and Perplexity and Google's Gemini and NotebookLM have features with the same name. Unlike a normal chat that answers right away, it takes time: OpenAI says 5 to 30 minutes. It is like handing a question to a librarian and getting back a report with a list of the materials they used.
Watch out Do not trust the report just because it lists sources. When OpenAI announced the feature, it wrote that the agent can still make up facts or reason incorrectly, and may struggle to tell trustworthy information from rumors. Before you base a decision on the report, check the important numbers and names in the original pages yourself, and since free plans allow only a set number of runs, save them for research you really need.
Source: OpenAI, “Introducing deep research” · Perplexity, “Introducing Perplexity Deep Research” · Google, “NotebookLM adds Deep Research and support for more source types” · Google, “Gemini Deep Research — your personal research assistant” (checked 2026-10-26)