Anime is a special case
Most television anime is produced at 1080p or below and upscaled, so the HD stream is the real one and a 4K stream adds little; the theatrical films are the exception and look superb in 4K on a 4K panel. The HD flag on every 9AnimeTV card says the anime plays in HD on the services in the Watch now list, and 1080p is the tier to expect on a television plan.
The year on the card
A 90s series was mastered from film or standard-definition video, and its HD release is as good as it will look; the classics shelf is honest about this. A 2026 simulcast is 1080p native. The service decides the tier from the master, your plan and the screen.
Data
HD needs about five megabits a second and uses one to three gigabytes an hour; a twelve-episode cour in HD is about six gigabytes, and about two at a service's data-saver tier. On a television over Wi-Fi none of this matters; on a phone on mobile data, the data-saver tier is the setting to choose, and the downloads page explains how to bring a cour down over Wi-Fi the night before.
When a stream buffers
Drop the tier one step in the service's player and it settles; a television on Wi-Fi at the far end of the house is the usual cause, and a wired connection or a closer access point is the lasting fix. The not working page covers the site's own loading problems.
