An assistant limited to your sources
Gemini Notebook is Google’s document-focused AI tool. It began as Project Tailwind in 2023, became widely known as NotebookLM, and was renamed Gemini Notebook in July 2026.
Add PDFs, web pages, video, audio, or documents and you can question them, summarize them, and build study material from them. Where general Gemini is a broad-knowledge assistant, Gemini Notebook is a librarian who has read exactly what you handed over.
Answering from sources is the point
Answers show which part of which source they came from, so you can return to the original and check. That makes it well suited to reading across several papers, meeting documents, or manuals at once.
It can also turn sources into audio explanations, video, study guides, and mind maps. Converting material into something other than reading supports learning while commuting and sharing within a team.
What changed with the rename
It remains an independent research tool. Beyond the name, notebooks can now be used from the Gemini app and synchronized with the standalone Gemini Notebook, and Google plans to make notebooks reachable from AI Mode in search.
A per-notebook secure cloud computer can also run code to calculate and analyze figures inside your sources. Availability varies by plan.
As a second brain
Collecting work material, research notes, and past articles into notebooks by theme gives you a personal knowledge base. Because the AI can search, compare, and reorganize it, the result is a workspace you think alongside rather than a filing cabinet.
Obsidian is strong at holding Markdown files under your own long-term control; Gemini Notebook is strong at analyzing and transforming material you have loaded. Storing in Obsidian and reading intensively in Gemini Notebook is a reasonable division.
Cautions
Even a source-grounded AI misreads tables and omits things in summaries. For anything important, follow the citation back to the source. For confidential material or personal data, check your organization’s policy and your plan’s data handling.