Download 4K YouTube Videos From IOS Via IMovie
If you try to download a 4K movie directly from the Photos app in iOS, the quality will automatically drop to standard definition. To get around this, you just need to use iMovie instead.
For some reason, the built-in YouTube downloader for iOS will let you upload 720p and 1080p videos to YouTube without any problem, but when you try to upload a 4k video, it only gives you a “standard definition” option. Gawker’s Shep McAllister pointed out to me that the best workaround for this is to simply use iMovie to download the video. After recording a video, simply upload it to iMovie, select the YouTube upload option and you’re done. This is a silly workaround, but it helps. You can always just share the video to your computer and download from there, but this is a good way to do it right from iOS.