There are several ways to download Avengers Infinity War in 720p, 1080p, or 4K. One option is to purchase the movie on digital platforms such as Movies Anywhere, Google Play, or the Microsoft Store. These platforms offer the movie in various resolutions, including 720p, 1080p, and 4K. Another option is to stream the movie on services such as Disney+ or Amazon Prime Video, which also offer the movie in different resolutions.
Alternatively, it is possible to download the movie from torrent websites or other illegal sources, but this is not recommended as it is illegal and can result in fines or legal consequences. It is always best to support the filmmakers and the movie industry by purchasing the movie legally.