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Documentation Index

Fetch the complete documentation index at: https://google-40.mintlify.app/llms.txt

Use this file to discover all available pages before exploring further.

A source is any document, file, or URL you add to a notebook. Sources are what the AI reads. When you ask a question, NotebookLM searches through every source in your notebook, finds the most relevant passages, and uses them to construct its answer. The AI never draws on outside information—only what you’ve explicitly added.

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Supported source types

NotebookLM accepts a range of content types:
  • PDF files
  • Google Docs
  • Google Slides
  • Website URLs
  • YouTube video links
  • Audio files
  • Copied and pasted text
For file size limits, format requirements, and a full breakdown of what each type supports, see Supported formats.

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How the AI uses your sources

When you add sources to a notebook, NotebookLM reads and indexes all of their content. That index is what the AI searches when you ask a question. The AI treats your sources as the complete scope of its knowledge for that notebook. If information isn’t in your sources, the AI won’t use it—and will tell you so rather than guessing.
NotebookLM’s AI never draws on knowledge from outside your sources. Its answers are grounded entirely in the content you’ve added to the notebook. This is by design: it keeps answers accurate, traceable, and relevant to your research.

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Source processing

After you upload or link a source, NotebookLM analyzes and indexes the content before the AI can use it. For most sources this takes only a few seconds. You’ll see a status indicator on the source while processing is in progress. Once it’s complete, the source becomes available for the AI to reference.
Large documents—especially lengthy PDFs or long audio files—may take longer to process. If you add several large sources at once, processing time can increase. The AI won’t use a source until it has finished indexing, so wait for all sources to show as ready before starting a research session.

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The 50-source limit

Each notebook can hold up to 50 sources. If you reach the limit, remove a source before adding a new one. To manage your existing sources, see Managing sources.

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Inline citations

Every answer the AI gives includes citation markers that link back to the specific source passages it used. Select a citation to jump directly to that section of the source. This lets you verify the AI’s reasoning, read the original context, and trace exactly where each claim came from. Citations appear automatically—you don’t need to ask for them. For more on how citations work, see Citations.

Add your first source

Step-by-step instructions for uploading files, adding links, and pasting text.

Supported formats

Full details on accepted file types, size limits, and format requirements.

Manage sources

Reorder, remove, or review the sources in your notebook.

Understand citations

Learn how inline citations work and how to use them to verify answers.