Three correct shapes, not one
There isn't a single "Instagram post size." Instagram's help page says photos are shared at up to 1080 pixels wide, at any aspect ratio between 1.91:1 (landscape) and 3:4 (tall) — for a 1080-pixel-wide photo, anything from 566 to 1440 pixels high (Instagram Help, checked 24 September 2026). Within that range, three shapes cover almost every post:
| Shape | Size | Use it for |
|---|---|---|
| Square, 1:1 | 1080 × 1080 | Product shots, quote cards, uniform grids |
| Portrait, 4:5 | 1080 × 1350 | The long-standing default for tall posts |
| Tall, 3:4 | 1080 × 1440 | The tallest shape Instagram accepts without cropping |
All three display at full resolution; none is a compressed version of another. Many size guides still stop at 4:5, while the help page now goes to 3:4. The practical difference is screen space: a taller post occupies more vertical height in the feed than a square from the same account, which is why many accounts default to tall shapes. Square still has its place for anything built around uniform tiles.
What the profile grid shows
The profile grid can show a cropped preview of a post rather than the whole image, and the preview shape has changed over the years. The full image is still what displays in the feed and when someone taps the post. If you want a tall post to read cleanly as a grid tile too, keep the subject in the middle two-thirds of the frame rather than right at the top or bottom edge, and both views will look intentional.
Why a focal point beats a centred crop
Most photos aren't already square or 4:5, so getting to either size means cropping something. A centred crop works fine when the subject is already in the middle of the frame, and fails the moment it isn't — a person standing to one side, a product placed off-centre for the original shot, gets sliced awkwardly out of the result.
Dragging the focal point onto the part of the photo that actually matters — a face, a product, a specific detail — fixes that in one step. Both the square and portrait crops are built around that point instead of the image's geometric centre, and if the point sits close to an edge, the crop slides inward rather than running off the photo.
Because both sizes come from the same source and the same focal point, you can preview one, adjust the focal point until it looks right, then switch to the other size and check it still holds up — before downloading either.
Start with a large source photo
Instagram re-compresses every image down to its own display size regardless of what you upload, so a 4000px photo and a 1080px photo of the same crop look identical once posted. What a larger source does help is the crop itself: more resolution gives the focal-point crop room to work with before detail starts to soften, so it's worth starting from the largest version of a photo you have rather than a pre-shrunk copy.
Batching several posts
If you're preparing more than one image at a time — a carousel, or a batch of posts for the week — export each one with its focal point set individually rather than reusing the same crop position across different photos. A focal point that's correct for a face in one photo will usually be wrong for a product shot in the next.
Output is JPEG at high quality, which is what Instagram re-encodes everything to anyway. Everything runs in your browser using the canvas API — the photo is never uploaded to a server, there's no sign-up, and no file size limit beyond what your own device can handle.