Watching 4K Netflix on a Mac is unnecessarily complicated. It's not currently supported in macOS, so you'll need to run Windows on your Mac---and even then you'll still be limited to the Edge browser. But it can be done.

Why is 4K Netflix an Issue for Macs?

The 4K content itself isn't the problem; it's an issue of compatibility, codecs, and DRM (Digital Rights Management). And it's not just Macs---4K streaming is an issue in general. When you stream video on any platform, it has to be packaged into something your computer can understand. The exact method for this is called a video coding format, and the program that does the packing and unpacking is called a codec. With the rise of 4K content, the tech world is currently in the process of switching over to newer codecs, and they're all fighting about it.

Codecs are built into your computer but can vary by browser. YouTube only uses the VP9 codec for 4K video, but Safari doesn't support VP9, so you need to use Chrome to watch 4K YouTube videos. Netflix supports a lot of codecs, but only uses HEVC for 4K. Since Safari is one of the few browsers to support HEVC playback, alongside Edge, it would seem 4K Netflix should be supported in Safari.

But another issue arises with DRM, a way of protecting the show from being copied and pirated. The DRM Netflix uses for 4K content is the new HDCP 2.2 (High-bandwidth Digital Content Protection), which macOS does not support as of Mojave. HDCP is an OS level compliance and can't be fixed with a fancier browser, so you'll need Windows (or a virtual machine running Windows) to watch Netflix, all to ensure you're not recording any shows. And the kicker is that DRM doesn't even really work since shows will be pirated regardless (often automatically within minutes of release), so all it does---especially in Netflix's case---is harm consumers.

You can still watch 4K Netflix content on your Mac, but it won't be easy, and it certainly won't be a good solution.

Running Windows on a Mac to Watch Netflix

In summary from above, you'll need:

• An HDCP 2.2 compliant 4K TV, if your Mac's built-in display isn't 4K or higher. Both the TV and HDMI cable have to be HDCP 2.2 compliant or nothing will work. You won't see any benefits streaming 4K content on a 1080p TV or your Mac's 1440p display since it's more pixels than can be displayed.
• A Mac with a Kaby Lake (or higher) Intel processor: Most Macs made after 2017 will have one. Only Kaby Lake or higher CPUs have specialized hardware for decoding HEVC much faster. Edge only supports hardware decoded HEVC, but since it's the only browser on Windows even supporting it at all, we have to use it. Safari does support software decoded HEVC on older CPUs, but since it doesn't support HDCP 2.2, we're stuck on Windows, using Edge. And even if you could use software decoding, you might run into performance issues depending on your model. Yeah, it's complicated.
• A Netflix "Premium" account, which costs $15.99 per month. This is the only plan with 4K support, but you will also be able to have four simultaneous streams from the same account.
• A copy of Windows 10 and the willingness to either dual-boot your system or run it in a virtual machine. You'll also need Edge, but it's included in Windows 10.

If you have everything on the list and really want 4K Netflix, the process of running Windows on Mac is fairly simple. You have a few options:

• Run a Windows virtual machine. A virtual machine runs Windows inside of macOS, so you don't have to switch over to Windows completely. You will notice a slight performance hit because you're running two operating systems at once. The VM we recommend for macOS is Parallels. It isn't free, so you can try VirtualBox if you'd like, but Parallels has much better performance and is built for macOS.
• Dual booting with Bootcamp, installing Windows permanently on your hard drive alongside (or on top of) macOS. This is an extreme solution, since you'll be forced to reboot into a different operating system to watch Netflix, but will offer better performance than the others. It's also less prone to bugs than VM software.
• Why not both? Parallels supports running your boot camp partition as a virtual machine. This way, you can boot fully into Windows if you'd like, but still be able to access it from macOS. If you've got the space on your hard drive, and don't mind the extra setup, this is the best solution.

Whatever option you choose, once you're running Windows, load up Microsoft's Edge browser and get to watching. You'll see a new category marked "Ultra HD 4K" containing all the UHD content. You can also use Netflix's Windows app, as it supports HEVC and HDCP 2.2. You can't use Google Chrome, Firefox, or another browser.

Ultimately, HDCP 2.2 is the primary issue, and as of macOS Mojave, HDCP 2.2 is still not supported. Support may be added to macOS sometime in the future, which will fix this mess. But this has been an issue for a few years now, so don't set your hopes too high. The Apple TV 4K supports 4K Netflix, so maybe Apple just wants you to buy that instead.