NotebookLM vs ChatGPT: a free notebook holds 3.3 times the text of a free ChatGPT project, but ChatGPT takes files up to 512 MB

Is NotebookLM better than ChatGPT?

NotebookLM is better than ChatGPT for your own files. Google renamed NotebookLM to Gemini Notebook on 16 July 2026, and every limit here comes from Google's and OpenAI's help pages, read on 12 October 2026. We turned both sets of caps into one unit: the most words of source a single notebook or project can take.

Google counts in words. Its sources help page says each source "can contain up to 500,000 words or up to 200MB for uploaded files", and a free notebook takes 50 of them. OpenAI counts in tokens. Its file uploads page caps a text file at 2 million tokens, and a free project takes 5 files. OpenAI's own token guide says a token is about three quarters of a word in English. So one full file is about 1.5 million words. Five of them make 7.5 million.

Pay about $20 and the gap grows. Google AI Pro at $19.99 lifts a notebook to 300 sources, or 150 million words. ChatGPT Plus at $20 lifts a project to 25 files, or 37.5 million. That's four times as much text on Google's side.

These are storage ceilings. They aren't reading speeds. Neither company says its model reads a full notebook in one pass, and ChatGPT Free's Instant model has a 27K token context window and takes about 12 pages of text as input, per the ChatGPT pricing page. Drafting is where ChatGPT pulls ahead. Google says its notebook chat answers only from your sources. OpenAI's projects page puts Canvas in every project, as a place "to draft documents, code, or layouts", and ChatGPT can add what it already knows. So ChatGPT is the better tool when the files feed a draft. NotebookLM is the better one when the answer has to come from the files.

How do NotebookLM and ChatGPT Projects compare on limits?

NotebookLM holds more sources, and ChatGPT holds bigger files. Here is each limit both companies publish, side by side.

Two rows decide most cases. A free ChatGPT account can only upload 3 files a day, so it needs two days to fill even a 5 file project. And a 400 MB recording or scanned book won't fit one NotebookLM source, while ChatGPT takes documents up to 512 MB.

OpenAI's projects page lists the per plan files and the sharing caps, and says you can make an unlimited number of projects. Google's plans page gives notebooks and sources per tier, and labels the table "Usage Limits (Subject to Change)". If your work lives in Slack or a Drive folder, ChatGPT links to it. If it lives on YouTube, NotebookLM reads the captions, up to 500,000 words a video.

Does NotebookLM cite its sources better than ChatGPT?

Yes. NotebookLM is the one that documents a citation on every answer from your files. Google's chat help page says: "Chat responses in Gemini Notebook only use data from your sources." The same page says it "uses direct quotes, text, and images from your sources as citations." You hover over one to see the full quote, and you click it to jump to that passage in the source.

OpenAI documents citations for the web, not for your files. Its ChatGPT search page says that answers which use web search "may include citations", each one opening its page. The projects page says ChatGPT "can use what you add to provide more informed answers", and it doesn't describe quoting a passage back. So on ChatGPT, ask for the exact quote and check it in the file yourself.

NotebookLM isn't sealed off any more, though. The same Google page now lists searching the web, running code and making files among the actions its chat can take for you. You choose which sources it uses for each question. For the prompts that keep any model honest about a file, see how to summarize a PDF with AI.

Is NotebookLM or ChatGPT better for studying?

NotebookLM is better for studying from your own readings. Google's education page says it can "instantly generate flashcards and interactive practice quizzes based exclusively on the sources you upload." It also builds study guides with key terms and essay questions, and a Guided Learning mode meant to build understanding instead of handing over quick answers.

Its Audio Overviews have no match in ChatGPT. Google's Audio Overview page lists four formats. Deep Dive, The Critique and The Debate use two hosts. The Brief is a single speaker in under two minutes. They come in 80+ languages. An interactive mode lets you stop the hosts and ask a question, in English only.

ChatGPT's study mode runs on every plan, but not on your project files. OpenAI's study mode FAQ says: "The Study option is not available in Temporary Chats, GPTs, or Projects." You can still upload notes to a normal chat and study from them there. ChatGPT is the better pick when the topic goes past your notes, and you want it explained from what the model already knows.

How much do NotebookLM and ChatGPT cost, and how much can you chat?

Both are free to start. Google's paid plans start at $4.99 a month and OpenAI's at $8, in US prices as of October 2026.

Google stopped counting chats a day. On 2 September 2026 it began moving consumer accounts to compute limits, per 9to5Google. Google's usage limits page says the budget weighs your prompt, the model, the chat length and the feature you use. It "refreshes every 5 hours until you reach your weekly limit", and you can see where you stand under Settings, then Usage. If you run out, Generate later queues a Studio job for when your budget comes back.

OpenAI sells free text chat as unlimited, but its free context window is the smallest on the pricing page, 27K tokens against 54K on Go and Plus. Prices come from Google's subscriptions page and the ChatGPT pricing page. For a long reading list on a budget, the free Google tier takes more sources (50) than ChatGPT Go or Plus does (25).

Should you use NotebookLM or ChatGPT?

Use NotebookLM when the answer must come from your sources. Use ChatGPT when your sources feed a draft, a plan or code.

Privacy is close. Google's privacy page says your notebook content "will not be used to directly train our foundational AI models, unless you choose to provide feedback." On personal ChatGPT plans you turn off Improve the model for everyone, under Settings, then Data controls. OpenAI doesn't use Business, Enterprise or Edu content for training by default, per its data controls FAQ.

Whizi fits a narrow case: you want ChatGPT, Claude and Gemini to read the same files without paying for all three. A Whizi project holds up to 10 pinned files of up to 10 MB each, and folds their text into every message. It loses badly on volume. Each file gives at most 32,000 characters, and the whole project stops at 120,000, roughly 20,000 words at about six characters a word. That's 4% of one NotebookLM source. On Pro at $29.99 a month, the same project goes to ChatGPT Sol, Claude Sonnet and Gemini models, side by side if you like. For a 300 paper reading list, stay on NotebookLM. The Gemini vs ChatGPT comparison covers the two chat apps themselves.