What is NotebookLLM and How to use?

What is NotebookLM?

• What differentiated value does NotebookLM offer in the ChatGPT era? Google's AI-powered research tool enables users to build personalized learning environments. It's like having your own dedicated tutor at an affordable cost. Access it via https://notebooklm.google.com or through mobile apps.
• NotebookLM generates various types of learning content—chat, text, audio, and video—based on user-uploaded sources (PDF documents, website URLs, YouTube video links) with minimal hallucination.

LLM Models Used by NotebookLM

• As of May 5, 2025, NotebookLM uses the fast-responding Gemini 2.5 Flash for Chat queries and the Gemini 2.5 Pro with state-of-the-art Thinking capabilities for Audio Overview generation. (Source: Officially confirmed by Simon Tokumine from Google Labs) [Related Link 1] [Related Link 2]
• Both Gemini 2.5 Flash/Pro models provide identical token limits: 1,024K maximum input tokens and 64K maximum output tokens.

Core Features of NotebookLM

• Powered by the latest Gemini 2.5 Flash/Pro model with a massive context window of up to 25 million words (approximately 25+ million tokens), it can comprehensively analyze diverse sources from lengthy PDFs to YouTube videos. Supported local file upload formats include: pdf, txt, md, 3g2, 3gp, aac, aif, aifc, aiff, amr, au, avi, cda, m4a, mid, mp3, mp4, mpeg, ogg, opus, ra, ram, snd, wav, wma.
• The direct YouTube URL support feature is an exclusive capability that no competing service currently offers. Users can utilize up to 50 videos (Plus: 300) as sources to generate 10-minute audio podcast summaries.
• The Audio Overview feature is particularly innovative—two AI hosts engage in professional podcast-style conversations to explain content, which is a unique differentiator unavailable in other services.

NotebookLM Plus Extended Capabilities

• Plus version provides 5x expanded usage limits compared to the free tier:
  • Maximum Notebooks: Free 100 → Plus 500
  • Sources per Notebook: Free 50 → Plus 300
  • Daily Chat Queries: Free 50 → Plus 500
  • Daily Audio Overviews: Free 3 → Plus 20
  • Daily Video Overviews: Free 3 → Plus 20
  • Customization Features: Free Not Supported → Plus Supported

How to Access NotebookLM Plus

• Individual users can automatically access NotebookLM Plus features through Google AI Pro subscription ($19.99/month or $199.99/year). [Related Link]

Gemini Benefits with Google AI Pro

• If you subscribed to Google AI Pro for NotebookLM Plus, you can also enjoy these additional benefits in the Gemini app:
  • Gemini 2.5 Flash/Pro models support up to 1,000,000 tokens for maximum context window during conversations. (Free tier is limited to 32,000 tokens)
  • Gemini 2.5 Pro model allows up to 100 queries per day. [Related Link]
  • Deep Research can be requested up to 20 times per day. [Related Link]
  • Veo 3 Fast videos can be generated up to 3 times per day. [Related Link]

Audio Overview Customization Usage

• Plus version enables detailed style specification when generating Audio Overviews. Users can freely adjust duration (from default 6-7 minutes), host tone and manner, expertise level, and more.

# Customization Example:
Analyze every line of the source material in detail.
Create a long form audio podcast, minimum 45 minutes. Take your time — no skipping.
For each line or event, break it down thoroughly, including tactical context, political implications, and any personal or cultural biases the hosts might inject.

References

• Reddit - r/notebooklm