Safari 14, introduced in the beta version of iOS 14 and macOS Big Sur, introduced support for HDR video and allowed Netflix users to watch content in 4K HDR and Dolby Vision for the first time.
As 9to5Mac pointed out, Netflix has long provided 4K content that can be viewed on other platforms (such as 4K Apple TV), but Mac users have been unable to enjoy it due to hardware limitations.
Safari in macOS Catalina and earlier versions limit Netflix content to 1080p resolution, but with the macOS Big Sur system, Netflix can work in 4K format and supports Dolby Vision and HDR10 for more vivid colors.
To watch 4K HDR content on a Mac, you need to use it on a Mac launched in 2018 or later, so if you use an older Mac, you will continue to be limited to 1080p resolution on Netflix.
In addition, tvOS 14 and iOS 14 are now compatible with YouTube’s VP9 codec. Users can watch 4K YouTube content on these platforms, but Safari 14 in macOS Big Sur does not yet support this codec.
