I uploaded to YouTube a 4K video of more than an hour in length, to be able to easily show it to family and friends, since it has a size of 21 GB that makes it impossible to send it to many people, both for space and for access to media that allow it. Having it uploaded, I deleted it from my computer, knowing that YouTube quality was enough for a video like that.
However, I forgot something that I already knew, and that is that once you have uploaded a video to YouTube, although the platform offers a download platform to recover the clips that you have uploaded, its compression is even higher than what it applies to web video playback. Thus, using the official function, and without opting for third-party download tools such as youtube-dl, which do download a higher quality version, I verified that my file had gone from 21 GB to 260 MB.
An hour of 4K video went to 720p with very low compression, and that may even be a good thing
The first thing you think when you get a 260 MB file after expecting to get a 21 GB file is “what a crappy thing“. YouTube could do more to help us get at least the video that it plays, which is better than the one that it later allows us to download. The evidence is that the video that we have uploaded is 4K, but when we download it, the only version available is at 720p.
Also, it’s more destructive than that, since the original file was a 45fps video, and what YouTube has downloaded for us is a clipped video at 25 fps. Of bit rate, better not to mention, of course, from 37.7 Mbps we have gone to 0.3 Mbps. However, there is even a good part. Compressing a video is not always easy, especially for people without knowledge, and getting a small file of usable quality, much less.
If you’re not in a hurry and don’t want to spend time compressing videos, uploading them to YouTube is an excellent option to obtain small files.
On Windows, right now there is no built-in tool that allows you to compress correctly, and in macOS there is QuickTime, and now we will see the results, quite improvable. Globally, we have great free tools like HandBrake, but to compress a 4K video of that size to 720p, on my MacBook Air M1 it took me over an hour, using software acceleration or graphics acceleration, with high resource consumption in both cases (all CPU in the first).
With Quicktime, I can open a file like the one I deleted at 21 GB and export it to 720p in just 18 minutes, and from that source size, the file has grown to 3.58 GBmaintaining the fps and with a bitrate of 6.4 Mbps. It is a much more usable size, but when comparing with a version downloaded from YouTube of the same file, I notice that the sharpness in aspects such as text is not really higher than in the file that YouTube delivers.
Obviously, on a professional level, the compression that YouTube applies to downloaded videos after uploading them is dramatic and makes them unusable. However, in my case I have found that as a backup tool first, and as a compression tool second, YouTube is extremely efficient. The upload is very fast with a fiber connection of 2022, and although it takes a long time to process the videos, in a few hours you can download them compressed with an ideal size to share on platforms such as Telegram, which have a file limit of 2 GB.
More than good or bad platforms we have to talk about platforms that we can squeeze in one way or another as users. YouTube will never be a place to upload videos and not worry, because Content ID can play tricks on us and as a conservation tool it is very destructive to quality. However, as a place to passively compress videos without having to install any software or subject our GPU to abuse, it is spectacular for how exaggerated it is precisely by reducing the quality so much.