When you copy a YouTube URL (even for a playlist), click in the WinX software to launch. You start with the "analyzer," which checks all the options. This tool also tried to default to the 1,920-by-1,080 version in MP4; I picked the 4K version (3,840 by 2,160 pixels) in WebM format, a subset of the MKV format—you can rename a .webm file to a .mkv and it'll work fine. In settings there are options to default to WebM at highest res. You can set up a number of videos to back up before you even click the download button. The 4K 575.4MB file took 1 minute and 39 seconds to download, more than double that of 4K Video Downloader.
If you want to download videos from all popular video streaming services, now you just need this free online video downloader as a single solution. It not only allows you to download online videos from YouTube, but also other websites, including Vimeo, Dailymotion, Vevo, Metacafe, LiveLeak, MyVideo, Facebook and so many more. No matter what website it may be, the performance will stay the same. There is no limitations - you can download as many videos as you want from a number of different websites.