Quick Verdict

NotebookLM excels at turning your documents into useful knowledge without making things up. Best for: researchers, students, content creators who need source-grounded answers. Rating: 4.5/5

Andrej Karpathy calls it "one of the most powerful uses of AI." Steven Johnson analyzed 8,000 quotes from 30 years of research. Medical students say the Audio Overview is "a game-changer." But not everyone agrees. Here is what real users actually say.

TL;DR: NotebookLM has a 13% hallucination rate vs 40% for ChatGPT. If you do research-based work and need source-grounded answers, this tool changes how you learn. If you need real-time web search or work with math and chemistry, look elsewhere.

What Works

13% hallucination rate (vs 40% for ChatGPT)
Audio Overviews in 50+ languages
Every claim cites your actual sources
Free tier is generous

What Does Not

Mobile app lacks creation features
Struggles with math and chemistry
Notebooks are isolated from each other
Desktop required for serious work

Getting started: NotebookLM is free at notebooklm.google.com. Upload PDFs, Google Docs, or web links to create your first notebook in under a minute.

What Real Users Love Most

The Audio Overview Effect

The feature users mention most often is Audio Overview. It converts your uploaded documents into a podcast-style discussion between two AI hosts.

"I love the mind map, flash cards, and conversation features. I use it for research methods and social psychology courses. The Audio Overview is honestly a game-changer for studying complex papers."

— Reddit user, r/notebooklm

"I uploaded my textbook chapters and class notes. Two AI hosts started explaining concepts I had been struggling with for weeks. They even debated different interpretations."

— Reddit user, r/notebooklm

"I use NotebookLM for board exam prep. I upload dense research papers and get back digestible audio explanations. Perfect for my commute."

— Medical student, App Store review

The Hallucination Advantage

According to a comparative study cited in user discussions, NotebookLM has a 13% hallucination rate compared to 40% for ChatGPT and Gemini when answering questions about uploaded documents.

Why? NotebookLM only knows what you upload. It cannot access the internet during regular conversations. It cannot make up facts that are not in your sources.

"I switched from ChatGPT for literature reviews because NotebookLM cites exactly where each claim comes from. Every quote links back to my actual PDFs."
— Researcher, Reddit

Key insight: The 13% vs 40% hallucination difference is why academics and researchers trust NotebookLM for source-critical work.

Expert Opinions

Andrej Karpathy

Former Tesla AI Director

Karpathy publicly praised NotebookLM as "one of the most powerful uses of AI" for research purposes. His endorsement carries weight in technical circles and drove significant attention to the tool.

Steven Johnson

Bestselling Author

Johnson uploaded 8,000 quotes collected over 30 years of research. NotebookLM organized them by theme, identified connections he had missed, and helped him find patterns across decades of reading. His experiment became a reference case for what the tool can do with large research collections.

What Real Users Criticize

Language and Logic Limitations

Not every subject works equally well.

"NotebookLM excels in English literature and humanities, but it struggles with logic-based subjects like Chemistry. When I uploaded organic chemistry notes, the explanations were technically accurate but missed the intuitive understanding I needed."

— Student, Reddit

"Math proofs do not translate well to audio format. The podcast hosts cannot show you equations step by step."

— Reddit user

The Mobile Gap

"Great app, but where are all the features? I can listen to Audio Overviews but cannot create Mind Maps, Reports, or Study Guides. Everything creative is desktop-only."

— App Store review

This limitation frustrates users who want to work on tablets or phones. The mobile app is essentially a playback device for content created elsewhere.

The Pricing Reality

Feature	Free	Plus ($20/mo)	Enterprise ($9/user)
Sources per notebook	50	100	600
Words per source	500,000	500,000	500,000
Audio Overviews	Limited	Unlimited	Unlimited
Deep Research	Very limited	Full access	Full access
Languages	50+	50+	50+
SOC 2 / HIPAA	No	No	Yes

Reddit users generally agree: the free tier is generous enough to test whether NotebookLM fits your workflow. Power users consistently say Plus pays for itself if you create more than a few Audio Overviews per week.

September 2025 Outage: On September 11, 2025, NotebookLM went down for over 4 hours. Audio Overviews, flashcards, quizzes, and reports all failed. Some users on Reddit reported losing custom content they had not exported. Google fixed it and communicated transparently, but if you are building mission-critical workflows, export your important notes regularly.

Multilingual Support

NotebookLM supports Audio Overviews in over 50 languages.

Spanish, French, Portuguese: Users report natural-sounding hosts with good pronunciation. The AI explains technical terms rather than just translating them.

Mandarin, Hindi, Japanese: Generally positive reviews, though some users note accent variations.

Interactive Mode: Currently English-only. Users in other languages can generate audio but cannot interrupt to ask questions mid-stream.

NotebookLM vs ChatGPT

This question appears constantly on Reddit. The community consensus:

Use NotebookLM when:

You have specific documents that must be the only source of truth
Hallucination would be costly (academic papers, legal research, medical info)
You need every claim cited to its source
You want to learn from your own materials

Use ChatGPT when:

You need general knowledge or creative brainstorming
The topic is common knowledge
Speed matters more than source accuracy
You want to generate new ideas, not synthesize existing ones

Most power users in the community use both tools daily for different purposes.

How to Start

Reddit r/notebooklm FAQ suggests this approach for beginners:

Go to notebooklm.google.com and sign in with your Google account
Create one notebook about something you are actively researching
Upload 3-5 sources (PDFs, articles, YouTube links, or pasted text)
Ask one specific question about the material
Generate one Audio Overview and listen while doing something else

Total time investment: under 20 minutes. If that experience feels valuable, explore further.

Frequently Asked Questions

Does NotebookLM work on mobile?

Yes. iOS has 4.8/5 (14K reviews). Android has 4.8/5 (103K reviews). However, creation features like Mind Maps, Reports, and Study Guides are desktop-only.

Is my data used to train Google AI?

No. Google explicitly states uploaded content is not used for training. Queries are not saved beyond your session.

What file types are supported?

PDF, Google Docs, Slides, Sheets, images, Word docs, YouTube links, audio files (MP3, WAV, M4A), and plain text.

Is there an API?

Enterprise customers only. No public consumer API has been announced.

How does it compare to Perplexity?

NotebookLM analyzes only your uploaded sources. Perplexity searches the live web. Choose based on whether you need source-grounded answers or general knowledge.

Final Verdict

Average ratings across platforms:

Google Play: 4.8/5 (103,000+ reviews)
App Store: 4.8/5 (14,000+ reviews)
G2: 4.0/5

NotebookLM is for you if: You do research-based work. You need to synthesize multiple documents. You want every claim grounded in your actual sources.

NotebookLM is not for you if: You need real-time web search. You work primarily with math, chemistry, or visual subjects. You want a mobile-first experience.

The user reviews are clear: for document-based research and learning, NotebookLM does something no other tool quite matches.

★★★★☆ 4.5 / 5

Who Should Use NotebookLM

Best for: Students, researchers, content creators

Skip if: You need real-time web search or visual subjects

Try it: notebooklm.google.com (free tier available)

Sources: r/notebooklm community, Google Play (103K reviews), App Store (14K reviews), G2, public statements from Andrej Karpathy and Steven Johnson