NotebookLM (Gemini Notebook) Review: Sources and Limits

Google renamed NotebookLM to Gemini Notebook in July 2026; it remains the same standalone research product. The workflow centers on the information you add. Choose it when you need to ask questions across a reading set rather than expecting a general search answer detached from those sources.

Public website check. Google's public announcement says NotebookLM is being renamed Gemini Notebook while remaining a standalone product. Official source.

Source-grounded responses, Audio Overviews and study-oriented outputs offer different ways into the same material. Inspect the source supporting an important answer. A fluent audio explanation can still simplify or misinterpret a document, so use the original text when exact wording or evidence matters.

A focused documentation exercise starts with two permitted sources on one topic. Create a notebook, add those sources and ask which passage supports a single specified claim. Open the cited passage and compare its wording, scope and qualifications with the answer. If the source does not support the claim, keep it unresolved and ask a narrower question; a fluent answer is not a reason to invent a reference.

Keep the source version with the check. If a Drive source is updated or access changes, apply the source-handling conditions below before assuming an earlier answer still reflects the same material. The suggested two-source comparison was not executed. The one-source citation check below tests a narrower task and does not rate Audio Overview quality.

Google's chat help says a user can choose which notebook sources the model should use, hover over a citation for the quoted text, and open that citation in context. That suggests a repeatable source check, especially when the answer will be reused outside the notebook:

This check depends on source access. The import guide says an inaccessible Drive source can continue to occupy a slot while being excluded from new responses. For a consequential claim, confirm the source still opens before forwarding an old answer. We imported one public web page and opened one citation; we did not test file uploads, withdrawn Drive access, conflicting sources or the model's accuracy across other questions.

In an already signed-in Chrome session, the AI agent added the public NASA Mars 2020: Perseverance page as a website source in a new Gemini Notebook. It asked for the rover's landing date and target crater, with a source citation. The response gave February 18, 2021 and Jezero Crater. Opening its first citation displayed the NASA source fields for Launch / Landing and Target; the dates and crater matched the answer. The source pane also showed the imported page text.

Practical result: this single public-page question was answerable from the imported source, and the citation made the two key facts inspectable without leaving the notebook. This is one successful check, not an error-rate measurement. We did not test whether a second source would change the answer, whether a private file would import, or whether an Audio Overview would preserve the same details. For a decision that depends on a number or quotation, open the cited passage and compare its exact meaning before reusing the answer.

Google's cited plan table lists Standard at 100 notebooks and 50 sources per notebook, Plus at 200 and 100, and Pro at 500 and 300. Other plans exist; sharing a notebook does not raise a collaborator's source limit. Check the badge and actual plan before treating another person's notebook capacity as your allowance.

The source-import guide lists PDFs, DOCX, TXT/Markdown, Google Docs, web pages, supported audio and other formats. It states a limit of 500,000 words per source or 200 MB for uploaded files. Import details differ: a web URL generally imports page text, while supported YouTube sources use transcripts. Not every embedded image or video becomes analyzed content. Google's current import guide says Drive sources sync automatically, with a manual Click to sync with Google Drive option. If the original file is deleted or access is withdrawn, that source becomes inaccessible in the notebook. It still uses a source slot but is excluded from responses and new Studio outputs. Check access as well as the saved answer before reusing research. A study queue adds practice scheduling; it does not make an inaccessible source current or supported.

Use the source-based product when the main question is what a defined reading set says. Start with the current account's source cap and supported import type; a video that only supplies a transcript is a different input from full audiovisual analysis. A separate practice queue is relevant after source checking, when the task becomes recalling or revisiting an unresolved idea. Buying capacity cannot make an unsupported answer supported.

Open Macaron chat to adapt the request below. Review account access and plan conditions before creating a tool.

Use a source-grounded notebook to examine material, and a tracker to decide what needs another attempt. A remembered answer and a source-supported answer are different things. Keep a source title or page reference with the question without assuming the tracker can inspect a Google notebook.

Suggested fields: Topic; source title; self-test question; next review; confidence; unresolved point.

Proposed checks with fictional data:

Illustrative exam-preparation scenario: after a source-based summary, close it and answer one question from memory.

Keep the exact supporting passage or its locator with a checked answer. If a later source revision changes that passage, mark the answer for review rather than keeping its old verified status merely because the notebook or study date still exists.

Macaron does not gain access to a Google notebook through this example. Use material you have permission to process and verify consequential answers against the source.

Explore Macaron for a personal tool you can adapt to this task.

How this review was checked: Review for Macaron, prepared with AI. An AI agent used an already signed-in browser session to import one public NASA page into Gemini Notebook, ask one factual question and open its citation. Private files, multiple-source synthesis, Audio Overview, plan limits and the proposed Macaron mini-app were not tested.

Review scope: NotebookLM, renamed Gemini Notebook in Google’s July 2026 announcement. The Macaron sample tracks follow-up questions rather than connecting to a Google notebook.

Sources reviewed: last updated November 5, 2026. Product details may change; confirm current information with the provider.

Corrections: contact@macaron.im.