Every social media app operates under the assumption that your carefully composed photo would look much better if its edges were aggressively chopped off. To prevent their compression algorithms from deciding where your borders end, you have to format your images exactly to their specs.
The Aspect Ratio Cheat Sheet
| Placement | Ratio | Ideal Pixels | Sarcastic Verdict |
|---|---|---|---|
| Instagram Story / Reel | 9:16 | 1080 x 1920 | Keep elements 250px away from the top/bottom so UI buttons don't block them. |
| Instagram Feed (Portrait) | 4:5 | 1080 x 1350 | The crop limit. If your photo is a 2:3 DSLR portrait, the app will shave off the sides. |
| Instagram Feed (Square) | 1:1 | 1080 x 1080 | Retro, but mostly used because people can't be bothered to fit modern crops. |
| X (Twitter) Feed Post | 16:9 | 1200 x 675 | Will support other ratios, but 16:9 is the only one guaranteed not to look weird in feeds. |
| TikTok Video | 9:16 | 1080 x 1920 | Same as Reels, but the right-hand overlay is even thicker. Keep content centered. |
How to Avoid the 4:5 Portrait Trap
Most DSLR cameras shoot in 2:3 aspect ratio (e.g. 4000x6000 pixels). Instagram's maximum portrait ratio is 4:5.
When you upload a 2:3 vertical photo directly, the app forces you to crop either the top (cutting off the sky) or the bottom (cutting off your subject's feet). The only way to preserve your original composition is to add letterbox padding to convert the 2:3 photo into a 4:5 container.
2:3 image
Auto cropped
4:5 padded
Perfect fit