A source is a static copy of a Google Doc or Slides you have access to, a PDF file, or text that is copied and pasted directly into the app. When using NotebookLM, the model will use the sources you upload to answer your questions or complete your requests.

NotebookLM can’t delete or edit your original files. When you upload a Google Doc or a local PDF file from your computer, the app makes a copy of the original file. NotebookLM doesn’t keep track of changes to the original doc automatically, including access to it, so you have to manually refresh any local file you uploaded or use the Click to Sync button to refresh imported Google Docs and Slides in the source viewer.

Source Overview

When you upload a new source to NotebookLM, the app instantly creates a source overview that summarizes the document and offers key topics and questions to ask. Think of it as a research assistant that helps you better understand the source material.


  • Right now, NotebookLM supports the following source types: Google Docs, Google Slides, PDF files, and copy-pasted text
  • Each source can contain up to 500,000 words. Each notebook can contain up to 50 sources. We’ll review these limits periodically to help determine the best user experiences
  • Avoid uploading documents with any personal or sensitive information (e.g. names, addresses, phone numbers) in them
  • Avoid uploading documents you don’t have the applicable rights to

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