Instagram will accept almost any image you throw at it, then crop it to fit its own grid. That means the size that actually matters isn’t the one you uploaded, it’s the one that survives the crop. Get the ratio wrong and your subject’s head ends up cut off in someone’s feed.
Here are the dimensions Instagram actually uses.
| Type | Size | Aspect ratio |
|---|---|---|
| Profile Photo | 320 x 320 | 1:1 |
| Feed Post (Square) | 1080 x 1080 | 1:1 |
| Feed Post (Portrait) | 1080 x 1350 | 4:5 |
| Feed Post (Landscape) | 1080 x 566 | 1.91:1 |
| Story / Reel | 1080 x 1920 | 9:16 |
| Carousel (Square) | 1080 x 1080 | 1:1 |
| Carousel (Portrait) | 1080 x 1350 | 4:5 |
| IGTV Cover | 420 x 654 | 1:1.55 |
| Ad (Square) | 1080 x 1080 | 1:1 |
| Ad (Story) | 1080 x 1920 | 9:16 |
Which size to actually use
For a normal feed post, portrait at 1080 x 1350 is the one worth defaulting to. It takes up more vertical space than a square image, so it holds a scrolling thumb’s attention a bit longer. Square at 1080 x 1080 still works fine and is the safer choice if your image genuinely doesn’t crop well as a portrait.
For Stories and Reels, 1080 x 1920 is the only size that makes sense, but the size alone won’t save you. Keep your subject and any text away from the very top and bottom of the frame, that’s where the username, caption, and interface controls sit, and they’ll cover anything you put there.
Carousels should stay consistent across every slide. Mixing a square first slide with a portrait second slide looks sloppy once someone starts swiping.
Format and common mistakes
Export as JPEG for photos and PNG only when you need transparency or sharp text. Don’t upload a 4000px screenshot and let Instagram recompress it, downscale to the actual target size yourself first, you’ll get a sharper result. A social media image resizer makes this a one-step job instead of fiddling in an editor.
The other common mistake is pulling a screenshot at some odd ratio, like a phone screen recording, and posting it as-is. Instagram will crop it somewhere you didn’t choose. Run your image through an Instagram image size checker before you post if you’re not sure it’ll crop cleanly, and lean on a full image size guide if you’re juggling more than one platform’s specs at once.
Also watch your file size. A 15MB image doesn’t look any sharper on a phone screen than a properly compressed one, and it just slows down your upload. An image compressor gets the file size down without a visible quality hit.