I was tasked by another developer to create a “YouTube downloader” app, as many of the ones he used no longer worked. I accepted the challenge. As with most of my apps, I wanted this to be public, but I faced a challenge: Hosting videos on my server (ie. downloading the MP4 and offering as a link) would quickly utilize a ton of resources (bandwidth and disk space), and also have a possibility of copyright infringement by hosting a copyrighted video.
What I came up with is a YouTube downloader web app that handles the MP4 streaming directly by the web browser. The results are an app that allows you to download YouTube videos as MP4s from the browser’s Save As function. Interestingly enough, this works flawlessly with Chrome on Desktop and Safari on mobile, but not Firefox..
You can find my YouTube Video Downloader here: https://youtube.unlimitedweb.space