The bookmarks manager will help to ... and can automatically remove not existing.

LinkCollector PC is a bookmarks manager to easily exchange a bookmarks between any supported browsers (such as Internet Explorer, Mozilla Firefox 2-3, Opera, Google Chrome). The program will help you to view all bookmarks of all installed browsers simultaneously. And you can copy only needed bookmarks from one browser to another. LinkCollector PC will find a bookmarks duplicates, will verify your bookmarks and discover that the links is dead or is alive.

LinkCollector Portable Edition is a bookmark manager that supports all major browsers, such as Firefox, Opera, IExplorer. The program allows you to synchronize bookmarks between different browsers and computers and it can be stored on a USB disk. Besides, it neither saves anything to system folders nor writes any data to the Windows registry. Its nice, intuitive interface will allow you to do everything you need with your bookmark in no time.