Gemini can only upload up to 10 documents at most. If you have more documents you want to feed into Gemini, you can upload them to Google Drive. Whether it’s hundreds of documents or folders with multiple levels, you can process them using the Ask Gemini feature, which is very convenient.
NotebookLM also supports document uploads, but it has limits on quantity: advanced users can support up to 300 per notebook, while free users can support up to 50.
In addition, the Gemini models in Google Drive and NotebookLM have some restrictions applied.
The Gemini in NotebookLM is “strict mode.” NotebookLM’s core selling point is Source-Grounding by default. Its first priority is “not to talk nonsense.” So it must and can only find answers from the documents. If the documents don’t say it, even if it “knows” the answer, it will often choose to say, “I can’t find relevant information in the documents,” or give a very bare-bones answer based only on document snippets.
Gemini in Drive is “lenient mode.” It has Source-Grounding functionality, but the restrictions are not strict. It is more like a “general-purpose AI that has read your files,” understanding both files and world knowledge.
And in the Gemini app, if you ask a question, it will combine its massive training data + web search + your input to synthesize the “best sounding” answer. It will automatically complete the logic based on context, and even moderately “fill in the blanks” to polish it.
Once you understand the positioning of different products and their official presets, you’ll know how to choose.