NotebookLM is Google’s grounded research assistant: upload up to 50 sources per notebook (PDFs, docs, websites, YouTube links) and every answer is cited to the exact passage it came from. It summarizes, compares, explains and – famously – generates Audio Overviews that turn your sources into a podcast-style discussion.
Unlike general chatbots, NotebookLM refuses to wander outside your material, which makes it ideal for literature reviews, legal discovery, competitive research and study. Free covers generous use; NotebookLM Plus (via Google One AI Premium or Workspace) raises limits and unlocks advanced models.