Fullscreen (or full screen) refers to the 4:3 (1.33:1) aspect ratio of early standard television screens and computer monitors. Widescreen ratios started to become more popular in the 1990s and early 2010s.

Film originally created in the 4:3 aspect ratio does not need to be altered for full-screen release. In contrast, other aspect ratios can be converted to full screen using techniques such as pan and scan,