1. Video Converter Free has limited functions of Video Converter Pro, it can only convert standard video/audio formats. What’s more, the online download function is limited to YouTube only.
2. Both Video Converter Pro and Ultimate can convert non-protected videos and audio files, download online videos and record videos.
3. Video Converter Ultimate has all the features of Video Converter Pro. In addition, it also supports converting DRM files as well as ripping&burning DVDs.
Click below link to find detail comparison.