Source types and file formats NotebookLM supports

NotebookLM accepts PDFs, Google Docs, Google Slides, websites, YouTube videos, audio files, and copied text. Full format details, size limits, and requirements.

NotebookLM can work with a wide range of source types, from uploaded PDFs and audio files to Google Drive documents, public web pages, YouTube videos, and pasted text. Understanding which formats are supported—and any limits that apply—helps you choose the right source type for your research.

Each notebook supports up to 50 sources. If you reach the limit, remove an existing source before adding a new one.

Source types at a glance

Source type	Format	Key limit
PDF	.pdf	500 MB per file, up to 200,000 words
Google Docs	Google Doc URL or Drive picker	Must be accessible to you
Google Slides	Google Slides URL	Text and speaker notes indexed
Website	Public webpage URL	Paywalled content not supported
YouTube video	YouTube URL	Requires available captions
Audio file	.mp3, .m4a, .wav, and others	Size and length limits apply
Copied text	Plain text	Pasted directly into the source box

Supported formats by source type

PDF

NotebookLM indexes the text content of PDF files, including scanned documents using optical character recognition (OCR).

Supported format: .pdf

Limits:

• Up to 500 MB per file
• Up to 200,000 words per document

Best for: Research papers, academic articles, reports, books, scanned documents, and any long-form content you want to query against.

OCR support means you can add image-based PDFs (such as scanned pages), though the quality of indexed text depends on scan clarity.

Google Docs

You can add a Google Doc by pasting its URL or selecting it through the Google Drive picker. NotebookLM indexes the document’s text content, including headings and tables.

How to add:

• Paste the Google Doc URL directly, or
• Use the Google Drive picker to browse and select a document

Requirements:

• The document must be shared with you or owned by you
• You may need to authorize NotebookLM to access your Google Drive the first time

What’s indexed: Text content, headings, and tables. Images and embedded media are not indexed.

Google Slides

Add a Google Slides presentation by pasting its URL. NotebookLM indexes text from both slides and speaker notes.

How to add: Paste the Google Slides URL

What’s indexed: Text on each slide and any speaker notes attached to those slides. Images, charts, and embedded media are not indexed.

Speaker notes are a useful way to add context or commentary that you want NotebookLM to reference during research.

Websites

NotebookLM fetches and indexes the visible text content of a public webpage at the time you add it as a source.

How to add: Paste any public webpage URL

Works best for: News articles, blog posts, documentation pages, and other text-heavy public content

Limitations:

• Paywalled or login-protected content cannot be accessed
• Dynamic pages that require JavaScript to render may not be fully captured
• The content is captured at the time of adding—updates to the page after that point are not reflected

If a page requires you to be logged in to view it, NotebookLM will not be able to retrieve its content.

YouTube Videos

Add a YouTube video by pasting its URL. NotebookLM uses the video’s captions or transcript as the indexed content.

How to add: Paste the YouTube video URL

Requirements: The video must have captions or a transcript available (either auto-generated or manually added by the uploader)

Not supported: Audio-only videos, videos with no captions or transcript, and private or unlisted videos without accessible captions

If a video does not have captions, NotebookLM will not be able to add it as a source. Check that captions are available on YouTube before attempting to add the video.

Audio Files

Upload an audio file and NotebookLM will transcribe it, then index the transcript as the source content.

Supported formats: .mp3, .m4a, .wav, and other common audio formats

What happens: NotebookLM transcribes the audio and uses the resulting text for all AI queries against that source

Limits: Size and length limits apply. Very long recordings may take more time to process.

Best for: Recorded interviews, lectures, podcasts, meetings, and voice memos

Transcription quality depends on audio clarity. Background noise or multiple overlapping speakers may affect accuracy.

Copied Text

Paste plain text directly into NotebookLM to use it as a source without uploading a file or linking a URL.

How to add: Select “Copied text” when adding a source, then paste your content into the text box

Best for: Short articles, email threads, meeting notes, excerpts, or any text you have copied to your clipboard

This is the fastest way to add text that is not in a file or accessible via URL. There is no file to manage—the text is stored directly in your notebook.