The short answer: Instagram’s profile grid no longer shows square thumbnails — it shows 3:4 portrait tiles. Your feed posts should still be 1080 × 1350 px (4:5), but the grid crops them slightly taller-relative-to-width, so anything critical needs to survive a 3:4 center crop.

What actually changed

For a decade the grid was 1:1 squares, and designers built “grid-safe” square crops into every post. Instagram replaced the square grid with 3:4 tiles to match how content is actually shot (vertical), rolling out through 2025. Two practical consequences:

Old square-planned grids broke. Carefully aligned 9-tile mosaics and square-centered faces got cropped on the sides.
Instagram added a grid-crop adjuster. On your own profile you can tap a post → ⋯ → Adjust preview to reposition how it crops in the grid, without editing the post itself.

The sizes that matter now

Surface	Ratio	Pixels	Rule
Feed post (portrait)	4:5	1080 × 1350	Still the right upload size — full guide
Profile grid tile	3:4	~1015 × 1350 of your 4:5	~3% shaved off each side
Reels cover in grid	3:4	center of 1080 × 1920	Top/bottom cropped hard
Stories/Reels	9:16	1080 × 1920	Unchanged

The math for a 4:5 post shown as a 3:4 tile: the grid keeps your full height and trims roughly 32 px from each side of a 1080-wide canvas. So the safe rule is simple: keep text and faces at least 60 px from the left and right edges and your posts look intentional in both the feed and the grid.

Designing carousels for the new grid

Only slide 1 of a carousel appears in your grid, which makes the cover slide do double duty: it has to stop the scroll in feed and look clean as a 3:4 tile next to its neighbors. Three habits that hold up:

Center the headline block. Side-anchored text is what the 3:4 crop eats first.
One visual per cover. Busy covers read as noise at grid-tile size (~150 px wide on a phone).
Consistent cover template. A repeating cover style turns your grid into a brand asset — which is exactly what a consistent Look system produces automatically across a month of posts.

CarouselMaker bakes these safe zones into every template, so slide 1 always survives the grid crop without anyone checking. See how the Look system works →