Is there a YouTube to NotebookLM extension?

Yes. Several Chrome extensions make it faster to send YouTube videos to NotebookLM. Kaptex is one of them — it injects a one-click "Add to notebook" button directly on YouTube, so you can save a video to any of your notebooks without switching tabs or copying the URL manually.

Natively, NotebookLM also accepts YouTube URLs in the source panel: paste the link, click Insert, and the transcript is imported. The extension approach is faster when you are deep in a research session and want to save videos without breaking your flow.

Kaptex also handles bulk imports — you can sweep all open browser tabs (including YouTube tabs) into a notebook at once, which the native NotebookLM interface does not support.