By Jay Lim · Updated November 13, 2026 · Figures checked against the official pages listed under Sources Free Handles One Project at a Time, Pro Handles an Archive If each project you study fits in 50 sources, NotebookLM Free is enough . That is the per-notebook cap without a paid AI plan, as of November 2026. Google AI Pro lifts it to 300 sources and raises the notebook count from 100 to 500. Pro is listed at $19.99 a month in the US, bundled with 5 TB of Google storage. The source cap is the number that decides it, because a research set split across notebooks can no longer be questioned as one. Confirm current pricing on the official site before you subscribe. What Changed in the Name and What Did Not Google’s help center now calls the product Gemini Notebook. Most people still search for NotebookLM, and the plan pages treat the two as the same tool. The tool works the same way under either name. You upload sources, and the assistant answers questions grounded in those ...