A NotebookLM alternative that keeps one library, not separate notebooks

What NotebookLM does better

It is free, with a lot of room. The free tier gives you 100 notebooks with up to 50 sources each, and a single source can run to 500,000 words. Paid Google AI plans raise every limit, up to 500 notebooks and hundreds of sources per notebook.

It reads almost anything. PDFs, Google Docs, Slides and Sheets, Word and PowerPoint files, Markdown, images, audio files, web pages, public YouTube videos and ePub books can all be sources, and sources imported from Google Drive re-sync every few minutes.

It turns sources into other formats. Beyond chat with inline citations, NotebookLM’s Studio makes Audio and Video Overviews, mind maps, flashcards, quizzes, infographics, slide decks and reports from a notebook, and Deep Research browses hundreds of websites to write a report for you. Memento does none of that.

It is everywhere Google is. There are native iOS and Android apps (with sharing into a notebook and offline Audio Overviews), more than 80 languages, notebooks that sync with the Gemini app, and sharing with up to 50 people as viewers or editors — or publicly, by link.

What Memento does differently

One library, not a notebook per topic

Google’s help center is explicit: “Each notebook is independent. Gemini Notebook can’t access information across multiple notebooks at the same time.” A notebook is the unit you think in. In Memento, a space is one library that keeps growing — this year’s meeting notes, last year’s contract, the article you shared from your phone this morning — and the assistant answers from all of it, citing the pages and sources it used.

The agent writes the wiki, not just the answer

NotebookLM keeps your sources as they are and answers from them. Its notes are ones you write, or chat responses you save — and a saved response note can’t be edited afterwards. Memento’s agent reads each capture and writes what it learned onto the right pages: the person, the project, the decision. It links them to each other, and it updates them when a later capture changes the picture. You get a wiki you can browse and edit like a document, not only a chat window.

Facts carry a status

Every fact the agent writes is marked confirmed, inferred or disputed, and cites the read-only source it came from. When two sources disagree, the page says so instead of picking one. Bigger edits — changing a confirmed fact, merging pages — wait in your inbox as a diff until you approve them.

It keeps working when you don’t

Google’s NotebookLM help pages describe no scheduled or background work, apart from Drive sources re-syncing. Memento files each capture in the background, and routines run a prompt of yours on a schedule — a morning brief, a Friday sweep of open questions — into the same library.

History, and a way out

NotebookLM’s FAQ says there is currently no way to recover deleted notes, and notes export to Google Docs, where later edits don’t sync back. Memento’s library is plain Markdown in a Git repository: every change, yours or the agent’s, is a commit you can undo, and the export is the whole thing — pages, original files and history.

Pick NotebookLM instead if …

… you are studying or researching a fixed set of documents and want to question them, hear them as an Audio Overview, or turn them into flashcards — or you want a free tool with generous limits and native mobile apps. Memento is for the knowledge you keep adding to for years. It is not a study tool, and filing a capture takes minutes of agent work (typically around eight), not seconds.

The two also combine well: a one-off deep dive in NotebookLM, and the conclusions — or the report it wrote — captured into Memento, where they are filed next to everything else you know about the subject.

Moving from NotebookLM

Your sources are the part worth bringing: the PDFs, documents and links you uploaded. Capture them into Memento — a bulk import files a whole folder in one pass. Notes you want to keep can go to Google Docs with NotebookLM’s own export, then come across as Word files like any other document.