Remarkable is a simple extension that automatically keeps your bookmarks clean & up-to-date.
Moves dead bookmarks (e.g. non-existent pages) to a folder called "Trash" for you to review. No bookmarks will be deleted.
Refreshes your bookmark favicons. All pages will be slowly opened and closed in batches, so can take some time. You can configure the batch size in the settings.
Remarkable doesn't receive or store any data about you or your bookmarks. The Chrome Storage API permission is simply used to allow for configuration of the batch size in the extension settings.