Source LM

Bulk-add sources to NotebookLM and Gemini Notebook: JSON datasets, 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 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 — pick a .json file, preview how it will be split into Markdown files packed to the notebook's word limit, then upload. Records are never cut in half, and re-running the same file adds only what is new. • YouTube videos, playlists and channels — an "Add to notebook" button inside YouTube's own interface, or pick videos from the extension popup. • 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 that cannot be fetched by a server (logged-in or JavaScript-rendered), the text is read from the tab you have open and converted to Markdown. • 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. HOW IT HANDLES YOUR DATA There is no server behind this extension and no account to create. Your files, pages and notebook contents never leave the browser: the extension acts inside your own signed-in tab, exactly as if you were clicking. It reads no data it was not pointed at, and stores only your settings and pending jobs locally. FREE AND PRO Single sources are free and stay free: one video, one link, one selection, one page, comments on their own. Bulk actions — a JSON file, a playlist, a list of links, a video together with its comments — are free for the first few uses, after which they need a one-time Pro licence. No subscription. The source code is published at github.com/source-lm/source-lm-extension. 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.