Get past the NotebookLM source limit.
A notebook caps how many sources you can add, and a big research pile blows past it fast. Drop the whole folder here instead. Everything, even the PDFs, is read in your browser and packed into one file, so a stack of documents becomes a single source.
- A whole pile becomes one source
- PDFs and Office docs read in-browser
- No sign-up, nothing uploaded
Drag your folder here
A whole research pile, read in a second.
Many documents, one source.
NotebookLM counts sources, not documents. When a folder of papers and reports becomes one file, it lands as a single source, so a pile that would use up your source count fits in one slot and NotebookLM still grounds its answers on all of it.
A file tree at the top keeps every document labeled
- before84 documents, 84 sourcesover 50
- 84 documents, 1 sourcefits
Where NotebookLM stops you.
A notebook caps the number of sources, and each source has a generous word limit. Combining into one file trades a long list of sources for a single one that still has room to spare.
| Where you add files | What it caps | Limit today |
|---|---|---|
| Sources per notebook | How many sources you can add | 50 on free, 100 on paid |
| Size per source | Words in a single source | Up to about 500,000 words |
Figures as of July 2026, and Google changes them often. Check the current numbers in the NotebookLM help center. On ChatGPT, Claude, or Gemini instead? See how to share all your files with any AI.
From a research pile to one source.
- 1
Drop the whole pile
Drag in every paper, report, and note you want the notebook to draw on. Subfolders come along.
- 2
It reads everything here
PDFs, Word, and notes are turned into text in this tab, with a file tree at the top. Nothing is uploaded.
- 3
Add the one file as a source
Upload the single file to your notebook, and NotebookLM grounds its answers and citations on the whole set from one source.
A reading pile, packed into one source.
A folder that would use up dozens of source slots goes in. One file comes out, labeled as documents, and it lands in the notebook as a single source.
literature-review/
├── papers/
│ ├── 2019-survey.pdf
│ └── 2023-methods.pdf
├── interviews.docx
├── field-notes.md
└── 80 more files<documents project="literature-review">
<summary>
This is a packed snapshot of a set
of documents, assembled by
fileconcat.com.
File count: 84.
</summary>
...One source, room to spare
The combined file is one source, and with boilerplate left out it sits well inside the per-source word limit, so a whole review still leaves you plenty of source slots free.
Common questions.
- How many sources can I add to a NotebookLM notebook?
- NotebookLM allows 50 sources on the free plan and 100 with a paid plan. Combining your documents into one file means a whole pile of documents arrives as a single source, so it fits well under the cap.
- Is there a size limit per source in NotebookLM?
- Yes. Each source can hold up to about 500,000 words. A combined file stays one source, and FileConcat leaves out boilerplate so the word count goes to the content that matters.
- Does combining files count as one source?
- Yes. However many documents go in, FileConcat returns a single file, so it is added to the notebook as one source, with a file tree that keeps every document labeled and in order.
- Can NotebookLM read the PDFs and Word files I combine?
- Yes. FileConcat reads PDF, Word, Excel, and PowerPoint files in your browser and turns them into text, so the combined source is plain text NotebookLM can ground its answers and citations on.
- Are my documents uploaded to a server?
- No. Every file, including the PDFs and Office documents, is read in your browser tab. Nothing is sent, nothing is stored, and there is no account to create.