Gregator vs NotebookLM

Pick NotebookLM when you already have the material: lecture notes, PDFs, slides, a reading list. It works on the sources you add and turns them into answers, audio, and study aids. Pick Gregator when you have only a topic and want a structured, cited course built for you from the open web.

A note on the name: Google renamed NotebookLM to Gemini Notebook on July 16, 2026. Google describes it as the same standalone product, so this post uses both names.

What NotebookLM does well

NotebookLM is built around a notebook of your own sources. Google's help center lists a wide range of source types: PDFs, Google Docs, Slides and Sheets, Word, PowerPoint, Markdown, CSV, ePub, images, audio files, web URLs, YouTube videos with captions, and pasted text. Each source can hold up to 500,000 words or 200MB for uploaded files.

It is not limited to what you upload. Fast Research pulls in web or Drive results for a query, and Deep Research is an agentic feature that, in Google's words, "can automatically browse up to hundreds of websites on your behalf." You review the results and choose which ones to import.

The output formats are its biggest strength:

Audio Overviews in four formats (Deep Dive, Brief, Critique, Debate), in more than 80 languages, with an English-only interactive mode where you can join the hosts and ask questions by voice.
Video Overviews built from your sources; in September 2026 Google announced short versions of about 60 seconds.
Flashcards and quizzes with easy, medium, or hard difficulty, an Explain button, saved flashcard progress, and CSV download for flashcard decks.
Interactive learning overviews under Reports, which combine summaries with infographics, quizzes, and flashcards. Google's September 2026 post says these are rolling out to all users.

In July 2026 Google added a secure cloud computer to each notebook, so it can write and run code for data analysis grounded in your sources. That is available first to Google AI Ultra users and some Workspace customers.

Limits are generous. The standard plan allows 100 notebooks per user and 50 sources per notebook; Google AI Pro raises that to 500 notebooks and 300 sources, and Ultra goes up to 600 sources per notebook.

How Gregator works differently

Gregator starts from a topic, not from your files. It does not take uploads. You type what you want to learn, and Gregator:

Plans a curriculum: a refined title, a summary, and 1 to 12 Chapters sized to the topic, each with its own objective and search queries.
Researches the open web across seven search providers, including arXiv and Wikipedia, and extracts up to 18 sources per Chapter, with at most 4 from one domain.
Writes each Chapter from its 7 most relevant sources, chosen with a cap on domain and perspective so one site does not dominate. Chapters run about 700 to 1,200 words and end with key takeaways.
Reviews the whole course for redundancy, difficulty spikes, coherence gaps, and one-sided sources on contested topics, and revises flagged Chapters automatically.

Citations are inline footnotes placed next to the claim they support, and each Chapter ends with a Sources list. Every source is classified for type (peer-reviewed, institutional, journalism, community) and evidence quality. You see a trust overview for the course, with the mix of source types and an evidence-quality label, and each Chapter shows its source and peer-reviewed counts. Individual source scores are not shown.

The course is saved, and the learning tools sit around it: up to 5 multiple-choice quiz questions per Chapter plus a final course quiz, graded on the server, where a wrong answer links back to the relevant section. Greg, the chat tutor, reads your Chapters, can search the course and the web, and can offer a deep dive that adds a new Chapter. Progress is tracked per Chapter and course, and you get recommendations for what to learn next.

Side by side

	NotebookLM (Gemini Notebook)	Gregator
Output	Chat answers, Audio and Video Overviews, reports, flashcards, quizzes, built from your notebook	A saved course of 1 to 12 Chapters, written from a topic
Sources and citations	Your uploads, plus web results you choose to import through Fast or Deep Research	Open web research across seven providers, including arXiv and Wikipedia; inline footnotes and a Sources list per Chapter
Source credibility	You choose the sources	Each source classified for type and evidence quality; course trust overview
Learning features	Flashcards, quizzes, Audio Overviews in 80+ languages, Video Overviews, interactive learning overviews	Server-graded quizzes linked to Chapter sections, Greg tutor, deep dives, narration on paid plans, progress and recommendations
Pricing (as of October 2026)	Free with a Google account; higher limits with Google AI Plus ($4.99/month), Pro ($19.99/month), or Ultra (from $99.99/month), US prices	Free: 3 courses in total. Starter: $9.99/month or $99.90/year, 5 courses a month. Pro: $19.99/month or $199.90/year, 20 courses a month
Best for	Studying material you already have	Learning a topic from scratch

When to choose NotebookLM

Your course or job already gave you the reading, and you need to study that exact material.
You want audio or video summaries, or you study in a language other than English. Gregator is English-first.
You work with private documents, spreadsheets, or recordings that are not on the open web.
You want very large notebooks or code-based analysis of your own data.

When to choose Gregator

You have a topic and no reading list, and you want the research and the structure done for you.
You want a course you can read in order, Chapter by Chapter, with footnotes and a Sources list in each one.
You want to see what kind of sources stand behind the course before you trust it.
You want quizzes graded against the course, a tutor that knows your Chapters, and progress you can come back to.
You want to share what you learned: a public course link can be read by anyone without an account, and you can export a course or Chapter as Markdown.

Gregator has limits worth knowing. It researches the open web only, so it will not read your files. It is English-first. There is no PDF export and no native mobile app; it runs as an installable web app. Narration needs a paid plan.

Many learners will use both: Gregator for a first course on a new topic, NotebookLM for the papers and notes they collect afterwards.