How to Match Ratios Across an Instagram Carousel

Published 2026-09-29

When you post multiple photos together on Instagram (a carousel), every photo is displayed at the ratio of the first one. If later photos have a different ratio, they get cropped or padded to match.

Why the first slide sets the ratio

To keep the carousel from jumping around as you swipe, Instagram locks the whole post to the height set by the first slide. Mixing a square photo with a portrait one means the square photo gets padding, or the portrait photo gets cropped top and bottom.

Combinations to avoid

Before you post

• Crop every photo to the same ratio ahead of time. 4:5 (portrait) is a safe default since it takes up the most feed space.
• Choose the first photo carefully — it decides the shape (portrait or square) for the entire carousel.
• If a landscape photo is essential, adding a matching background color or a blurred fill above and below to fit the 4:5 frame looks more intentional than letting Instagram crop it.

How to do it in prezll

1. Upload each photo for the carousel to prezll one at a time.
2. Open the Crop tool and choose the Instagram 4:5 preset, or whichever ratio you've settled on.
3. Apply the same preset to every photo — only the crop position needs adjusting per photo, not the ratio itself.
4. Download each photo and upload them as a carousel in the Instagram app, in order.

The composition can differ from slide to slide, but as long as the ratio matches, the carousel scrolls smoothly at one consistent height.