How many sources can NotebookLM hold?
Free tier: 300 sources per notebook. Plus tier: 1,500 sources per notebook. The free tier was 50 in early 2024 and increased to 300 in 2025 — sufficient for serious literature reviews.
In more detail
NotebookLM's per-notebook source limit was a key bottleneck in 2024 (50 sources only) and became a major upgrade target. Late 2024 / early 2025 increases: free tier moved to 300 per notebook (6x increase); Plus tier set at 1,500. Per-source word/size limits: 500K words or 200 MB. Total notebooks per account: 100 free / 500 Plus. For most academic literature reviews and team research projects, 300 sources is sufficient. For multi-year dissertations or institutional knowledge bases, Plus's 1,500 limit matters.
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Notebook Toolkit saves ChatGPT, Claude, YouTube, Reddit, and any web page to NotebookLM in one click. Free to install.
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