Source LM EN

Bulk-add sources to NotebookLM and Gemini Notebook: JSON datasets, Telegram exports, Notion pages, YouTube videos, link lists, web pages.

NotebookLM takes sources one at a time, through a file picker. Source LM takes the batch.

Point it at a JSON export, a Telegram export, a YouTube playlist or a list of links, and the sources land in the notebook you already have open. Nothing is downloaded to disk first: files are built in memory and sent through the notebook page's own upload path.

WHAT YOU CAN ADD

• JSON datasets and Telegram HTML exports — pick the file, preview how it will be split into Markdown sources, then upload. NotebookLM allows 500,000 words per source; the extension packs to a budget of 400,000 rendered words. Records are never cut in half, and re-running the same file adds only what is new — the check runs against the source names already in the notebook, nothing is kept locally.
• Notion pages — an "Add to NotebookLM" button in Notion's own top bar. One click adds the page you have open; tick "Include child pages (1 level)" and its direct child pages come along, each as its own Markdown source. In your own workspace the page is fetched through Notion's own Markdown export; on a published *.notion.site page it is read the same way the site itself draws it. No API key, no integration token, nothing written to disk.
• YouTube videos, playlists and channels — an "Add to notebook" button inside YouTube's own interface, or pick videos from the extension popup. A channel brings in its latest N videos (50 by default).
• YouTube comments — the top comment threads with their replies, saved as a separate Markdown source.
• Web pages — paste one link or a whole list, one per line. For pages NotebookLM cannot fetch (logged-in or JavaScript-rendered), "Add page as .md" reads the text from the tab you have open.
• Selected text — select, right-click, "Add selection to Notebook", choose the notebook.

ON THE NOTEBOOK PAGE

• Filter the source list by typing a few letters.
• Select duplicate sources in one click.
• Delete every checked source in one batch, after a confirmation that lists what is about to go.
• Find sources that failed to import and capture them again from an open tab.

FREE AND PRO

$29 once. Not a subscription. Without paying you get 5 bulk actions per month, reset on the 1st. Single sources — one page, one link, one video, one Notion page, comments on their own — and deleting sources are always free and never counted. A Notion page taken together with its child pages is one bulk action.

HOW IT HANDLES YOUR DATA

There is no server behind this extension and no account to create. Traffic goes only to the notebook's own origin, Google's upload endpoint and the licence check — plus Notion's own origin when you press the button on a Notion page, in the tab you are already signed into. No proxy, no telemetry, no analytics. The extension acts inside your own signed-in tab and stores only your settings and pending jobs locally.

The source code is published unobfuscated at github.com/source-lm/source-lm-extension under PolyForm Noncommercial 1.0.0.

Source LM is an independent project. It is not created by, affiliated with, endorsed by or sponsored by Google. NotebookLM, Gemini and YouTube are trademarks of Google LLC; Notion is a trademark of Notion Labs, Inc. NotebookLM changes its interface from time to time; behaviour may change with it.