The HD badge
The white HD badge on every card is MyFlixer's standard. Every title listed exists in a proper high-definition release, and Watch now takes you to services that carry it in that quality. Nothing here is a camera recording or a soft standard-definition transfer.
720p, 1080p and full HD
Both are high definition. 1080p is the full HD frame and 720p is the smaller one; the difference shows on a television and disappears on a phone. Sharpness comes from the bitrate a service uses and the master the studio supplied, which is why a well-encoded stream looks better than a starved one at the same resolution.
4K and HDR
Recent films, prestige series and the newer anime films were finished at or near 4K, and on a large screen that tier is worth choosing. Many services also carry HDR, which widens the range of light and colour and is often the more visible upgrade. A series from 2005 was mastered in HD, so its 4K stream is an upscale; it still looks clean, but the money is better spent elsewhere.
Getting the best picture
On a television, choose the highest tier the service offers and let the TV handle the upscaling. On a laptop, 1080p is the sweet spot. On a phone, HD is indistinguishable from 4K and uses a fraction of the data: roughly one to three gigabytes an hour for HD against six to eight for 4K, which matters on a metered connection. Download in the service's app over Wi-Fi if you are going to be away from it.