Telemetry

Statistics and metrics

LM Subs reports the same numbers on the website, in the extension settings page, and in the toolbar popup, because all three read one shared report. Nothing is sent anywhere unless you sign in and turn sync on.

Captioning metrics

• Videos captioned, with the minutes of spoken audio indexed.
• Caption cues generated, plus cross-device cache hits.
• Video upload avoided, measured by comparing the extracted audio stream against the original video size.
• Median speed per caption request, with rate-limit failovers and export counts.

NotebookLM workspace metrics

• Notebooks used and sources indexed.
• Time watched and listened, including time saved by playback speed.
• Studio artifacts, split into Video Overviews and Audio Overviews.
• Citations sent to chat and bookmarked moments.

Sample data is labeled

The statistics page can show an illustrative sample dataset so you can inspect the layout before you have generated anything. The toggle is off by default and the page says clearly when the numbers are sample data.