Currently, macOS does not support Netflix playback in 4K HDR. The upcoming macOS Big Sur update, expected in late 2020, will enable this feature—but only on select models released in 2018 or later.
macOS Big Sur promises to bring Netflix 4K streaming to Macs, building on Apple's hardware advancements. To enjoy this, you'll need:
The key requirement is Apple's T2 Security Chip, a custom silicon component that integrates multiple controllers for enhanced security and performance. As Apple states, "by redesigning and integrating multiple controllers found in other Mac computers...the T2 chip brings new capabilities to your Mac."
Neither Apple nor Netflix has detailed the reason, but experts at The Verge suggest the T2's native HEVC codec support and fast video processing enable smooth 4K playback. Note that 4K streaming demands a robust internet connection due to high data usage.
These models include the T2 chip and will support 4K Netflix:
To verify your Mac's T2 chip:
4K Netflix has long been available on platforms like Windows 10 PCs and streaming devices such as Roku Premiere.