The Pixel Math Behind Seamless Instagram Carousels

A seamless carousel is a geometry problem before it is an export problem. If one portrait slide is 1080 × 1350 px, the master canvas must be an exact multiple of 1080 pixels wide: master_width = slide_width × slide_count master_height = slide_height Examples: Slides Master canvas 3 3240 × 1350 5 5400 × 1350 7 7560 × 1350 Why seams break The most common failures happen before slicing: The master image was resized to a width that does not divide into whole pixels. Text, faces, or logos sit directly on a cut boundary. Individual tiles are resized again after export. Filenames do not preserve the posting order. Different compression settings are applied to different tiles. A reliable export workflow Choose the final slide ratio. Multiply the slide width by the number of slides. Add guides at every slide boundary. Finish the composition on the single master canvas. Export the master once. Split it into equal horizontal sections. Test