Google NotebookLM has become a popular research tool for students, professionals, and content creators. But one question keeps coming up: how many sources can you actually use?
The answer depends on which plan you're on. NotebookLM's free version caps you at 50 sources per notebook. The Plus tier increases that to 300. The new Ultra tier goes up to 600. For many users working on large research projects, these limits create real friction.
This guide breaks down exactly what limits exist on each NotebookLM plan, what those limits mean for your workflow, and what alternatives exist if you need more flexibility.
Let's get into it.
NotebookLM Free Plan Limits
The free version of NotebookLM gives you enough to test the platform, but the caps show up quickly for serious work.
Source Limits:
- 50 sources per notebook
- 100 notebooks total
- 500,000 words per source
- 200MB maximum per uploaded file
Daily Usage Limits:
- 50 chat queries per day
- 3 audio overviews per day
- 10 Deep Research sessions per month
For casual users exploring a single topic with a handful of documents, these limits work fine. But for researchers building a large knowledge base or content creators producing regular audio overviews, hitting walls becomes routine.
The 50-source cap means you cannot add an entire book collection or full course material to one notebook. You end up managing which sources to keep and which to delete, which defeats the purpose of having an AI research assistant.
NotebookLM Plus Limits ($19.99/Month)
NotebookLM Plus comes bundled with Google One AI Premium at $19.99 per month. You cannot purchase it separately but it is included in Gemini Advanced, AI features in Gmail and Docs, and 2TB of cloud storage.
Source Limits:
- 300 sources per notebook (6x free)
- 500 notebooks total (5x free)
- 500,000 words per source (same as free)
- 200MB maximum per uploaded file (same as free)
Daily Usage Limits:
- 500 chat queries per day (10x free)
- 20 audio overviews per day
- 20 Deep Research sessions per day
Plus removes the immediate friction for most professional users. Three hundred sources per notebook handles most research projects. Five hundred daily queries means you can actually use it throughout a workday without watching a counter.
Students in the US (18+) get a 50% discount at $9.99 per month for the first year.
NotebookLM Ultra Limits ($249.99/Month)
Google announced NotebookLM Ultra in 2025 as part of the Google AI Ultra tier. This is the highest capacity option for power users and enterprise teams.
Source Limits:
- 600 sources per notebook (12x free)
- Higher notebook limits
- 500,000 words per source (same across all plans)
- 200MB maximum per uploaded file (same across all plans)
Daily Usage Limits:
- 5,000 chat queries per day
- 200 audio overviews per day
- 200 video overviews per day
- 200 Deep Research sessions per day
At $249.99 per month, Ultra targets organizations and heavy professional users. The 600-source cap is the highest NotebookLM offers, but the per-source word limit stays the same.
The Real Problem with NotebookLM's Limits
Source caps are not the only limitation. Three structural issues affect all NotebookLM plans:
1. Cloud-Only Operation NotebookLM requires an internet connection. There is no offline mode on any plan. Your documents live on Google's servers, processed through their infrastructure.
2. Single AI Provider You can only use Google's Gemini models. There is no option to bring your own API keys or use alternative AI providers like OpenAI, Claude, or local models.
3. Limited Integrations NotebookLM connects primarily to Google apps such as Drive, Docs, Slides, and Sheets. If your notes live in Apple Notes, Obsidian, Notion, or other tools, you need to export and re-upload manually.
For users with privacy requirements, offline needs, or existing note-taking systems outside Google's ecosystem, these limitations matter more than source counts.
What Is Elephas?
If NotebookLM's limits do not work for you, Elephas is worth considering. It is a Mac-native AI knowledge assistant built for users who need more flexibility than cloud-based tools offer.
Elephas lets you create personalized "Super Brains" from your documents. You upload files, and Elephas indexes them locally on your device. Then you chat with your knowledge base, ask questions, and get answers with source citations, similar to NotebookLM but without the caps.
The app supports 20+ file formats including PDFs, Word documents, Excel files, Markdown, Apple Notes, Notion exports, Obsidian vaults, web pages, YouTube transcripts, and audio recordings. That is broader format support than NotebookLM offers.
Unlike NotebookLM's monthly subscription model, Elephas offers one-time purchase options alongside subscriptions. More than 3,000 professionals use it for research, writing, and knowledge management.
Pricing: $9.99/month
Source Limits and Privacy: Elephas vs NotebookLM
On Source Limits:
NotebookLM caps you at 50-600 sources depending on your plan. Even the $249.99/month Ultra tier maxes out at 600 sources per notebook.
Elephas has no source limits. Add as many documents as your Mac can store. Your knowledge base grows without forcing you to delete older files to make room for new ones.
On Data Privacy:
NotebookLM stores everything on Google's servers. Google states they do not train models on your data, but your documents still leave your device for processing.
Elephas keeps all data on your Mac. Nothing leaves your device unless you choose to use cloud AI providers. For lawyers, healthcare professionals, or anyone handling sensitive information, local storage matters.
On Offline AI:
NotebookLM has no offline mode on any plan. You need an internet connection to use it.
Elephas includes built-in local AI models that run entirely on your Mac. No data sent to any server. You can also connect Ollama for additional local model options.
Local AI is optional; you can still connect to ChatGPT, Claude, Gemini, Perplexity, or Grok through your own API keys. The choice is yours.
Features NotebookLM Does Not Have
Workflow Automation:
NotebookLM is primarily for chat and audio overviews. You upload sources, ask questions, and generate podcast-style summaries.
Elephas lets you build multi-step AI workflows to automate tasks. Create workflows for summarizing files, running web searches, or generating diagrams. Chain AI agents together to handle routine work without manual intervention.
App Integrations:
NotebookLM connects with Google apps Docs, Drive, Slides, and Sheets. Third-party app support requires manual export and upload.
Elephas integrates directly with Apple Notes, Obsidian, Notion, LogSeq, Roam Research, and DEVONthink. Import Zoom meeting transcripts automatically. Add entire websites through sitemap extraction. Auto-sync keeps all connected apps updated without manual file management.
Platform Access:
NotebookLM runs only in a web browser. No native desktop or mobile apps.
Elephas is a native application for Mac, iPhone, and iPad. Access your knowledge base from any Apple device. The Mac app works system-wide through keyboard shortcuts, so you can query your Super Brain from any application without switching windows.
NotebookLM vs Elephas: Side-by-Side
Feature | NotebookLM | Elephas |
|---|---|---|
Source limit | 50-600 (by plan) | Unlimited |
Offline mode | Not available | Built-in local AI models |
Data location | Google servers | Your Mac only |
Platform | Web browser only | Mac, iPhone, iPad |
Pricing | Free or $19.99-$249/month | One-time purchase available |
Own API keys | Not supported | ChatGPT, Claude, Gemini, Grok, Perplexity |
Workflow automation | Not available | Yes, with AI agents |
Integrations | Google apps | Apple Notes, Obsidian, Notion, more |
Audio overviews | Yes | No |
NotebookLM works well for users who stay within its limits, prefer browser-based tools, and are invested in Google's ecosystem. Its audio overview feature is genuinely useful and unique.
Elephas fits better for Mac users with large document collections who want privacy, offline access, and freedom from monthly subscription fees.
Which One Should You Pick?
Stick with NotebookLM if:
- Your projects need fewer than 50 sources
- You prefer browser-based tools over native apps
- Cloud storage works for your documents
- You already use Google Workspace for everything
- You want audio overview generation
Consider Elephas if:
- You keep hitting NotebookLM's source limits
- You work with sensitive documents that should not be on Google's servers
- You want offline access without internet dependency
- You prefer native Mac apps over web tools
- You need integrations with Apple Notes, Obsidian, or Notion
- You want to avoid monthly subscription fees
- You need workflow automation for repetitive tasks
- You want to use your own API keys with multiple AI providers
Both tools serve different needs. NotebookLM is accessible and free to start. Elephas requires Mac hardware but removes the structural limitations that frustrate power users.
Final Thoughts
NotebookLM's source limits range from 50 on the free tier to 600 on the $249.99/month Ultra plan. For most casual users exploring single topics, the free tier handles things fine.
But if you find yourself constantly managing which sources to keep, need offline capability, or handle documents that should not leave your device, those limits become obstacles rather than guidelines.
Elephas removes those restrictions entirely. Unlimited sources, local processing, native Mac integration, and one-time purchase pricing. If NotebookLM's caps are slowing you down, try Elephas for free to see the difference.
