What matters
Instagram Carousel dimensions at a glance
Carousel posts in portrait 4:5 format are among Instagram's highest-engagement content types. The 1080×1350 canvas takes up more vertical feed space than square posts and supports up to 10 swipeable slides.
The 4:5 ratio occupies roughly 25% more screen real estate than a 1:1 square in the feed, giving your content a significant visibility advantage. Carousels also get re-shown by the algorithm when users don't swipe through all slides on the first pass.
Mixing aspect ratios across slides forces Instagram to crop or letterbox individual frames, creating an inconsistent swipe experience. Uploading at lower resolution results in noticeable softness after compression.