To watch 4K videos on YouTube, you don't necessarily need a 4K monitor, but having one will provide the best viewing experience. If you don't have a 4K monitor, the 4K video will either be downscaled on a lower-resolution monitor or upscaled on a higher-resolution monitor. However, to watch 4K YouTube videos on YouTube TV in 4K, you'll need an existing YouTube TV subscription, which costs $73 per month as of September 2