NotebookLM's biggest advantage is that it remains grounded in sources you upload. What this essentially means is that the tool only references material you've uploaded to a specific notebook (or information you've shared with the tool via the Chat panel). The only feature in the tool that resorts to searching the web is the Discover Sources feature Google added a few months back, which lets the AI find sources to add to your notebook based on a prompt you provide.

Though I had some doubts about the feature at first and thought it might be a step away from what makes NotebookLM unique, it turned out to be a pretty great addition. At the end of the day, you're still in control of which sources you add. If you don't like a webpage NotebookLM pulled and don't think it could be a meaningful addition to your notebook, simply don't add it. The feature isn't pushed on you either — you're free to ignore it all you want. Well, the Discover Sources feature just got an addition you don’t want to ignore: Google Drive integration.

NotebookLM just introduced Google Drive search, and it’s surprisingly good

When using NotebookLM to prepare for a quiz a few minutes ago, I decided to hit the Discover Sources button to quickly find more preparation materials in addition to the lecture slides my professor provided. I then spotted a new Find sources from header, with two clickable options: Web and Google Drive. Previously, the Discover Sources pop-up only had a text box to describe what you wanted NotebookLM to find.

For instance, you could simply say “Healthy lunch ideas,” and NotebookLM would instantly search the web and find multiple high-quality sources for you. Now, you can do the same thing by selecting Web under the Find sources from header. When you switch to the Google Drive option, according to NotebookLM itself, you can type stuff like “docs about Q4 planning,” “slides from Tim,” “notes from last week,” etc.

Since Google is yet to announce this feature via an X post or through it's The Keyword blog, I don't have the specifics on how it fully works just yet — but from my quick testing, it seems to scan your connected Google Drive for relevant documents matching your prompt. For instance, I typed “Linear Algebra,” and NotebookLM pulled up ten different documents I had saved in my Google Drive.

Some of them weren't exactly related to the linear algebra course I was referring to. For example, the search included a textbook I had saved during high school. However, this isn't surprising, since the book in question did mention linear algebra a few times throughout its chapters. Still, it’s impressive how quickly NotebookLM was able to surface those files. The results appeared almost instantly, and the tool even included a brief description of each document.

Now, I do think the feature isn't perfect yet. For instance, I reviewed the Logitech MX Master 4 a few days ago, and my Drive has an entire folder with material about it, like the specs sheet and the press release. Unfortunately, none of these documents showed up. The following error appeared:

When I tried the word “Logitech” alone, a couple of documents from my Drive did pop up, but still none related to the MX Master 4. One possible explanation for this is that NotebookLM might currently only be able to search through documents that are set to Public access rather than private files. If that’s the case, it would make sense why certain Drive items weren’t showing up in the results. However, I've reached out to Google for clarification on how exactly the Drive integration works and whether file permissions affect search visibility.

TestingCatalog did mention back in June that Google was working on Drive search integration for NotebookLM, along with Flashcards. So, it’s safe to assume Google’s now rolling this feature out more widely. Like Discover Sources for web-based results, I don’t think this new addition compromises NotebookLM’s source-grounded identity. In fact, since Drive searches are limited to your own content, the tool’s essentially just getting smarter about how it surfaces what you already have.