Ought saves your workspaces (names and URLs) and your light/dark theme choice locally in your browser, through the standard browser storage API. None of it leaves your device or gets shared with anyone.
The extension also runs a small script on YouTube watch pages that notes the video ID, title, and your current playback position, saved the same way — locally, so a later version of Ought can resume a video where you left off. That data stays on your machine too.
There's no analytics and no account required. Nothing that identifies you personally is collected. You can clear everything at any time by removing the extension or clearing its storage from your browser's settings.