Aspect ratio is the proportional relationship between the width and height of an image or video frame, expressed as two numbers separated by a colon. It defines the shape of the frame - how wide it is relative to its height - and is one of the most fundamental technical specifications in visual production because it determines how content is composed, how it fills different screens, and how it will be cropped or letterboxed when displayed on devices with different native shapes.

Common aspect ratios in contemporary production include 16:9 (widescreen, the standard for television, online video, and most monitors), 9:16 (vertical, used for mobile-first social media content on platforms like TikTok and Instagram Reels), 1:1 (square, associated with Instagram's original format and certain artistic contexts), 2.39:1 or 2.35:1 (cinemascope anamorphic widescreen, the ultra-wide format of theatrical blockbuster cinema), and 4:3 (the older television standard, now used for stylistic effect or archival contexts). Each ratio carries different compositional possibilities and cultural associations - ultra-wide cinemascope feels epic and theatrical, square feels graphic and social-media native, vertical fills mobile screens fully. Shooting or generating in a ratio that doesn't match the final delivery format requires either cropping, which loses image area, or letterboxing/pillarboxing, which adds black bars.

Specifying aspect ratio is an important first decision in any AI generation workflow. Generating content in the ratio intended for final delivery avoids reframing in post-production and ensures that compositional choices made at the prompting stage translate directly into the finished output. On Morphic, aspect ratio selection is available as a generation parameter, allowing creators to match the format of generated content to its intended platform from the outset.