Why Instagram makes your photos look worse
Every image you post is resized and re-compressed on Instagram's servers. Upload a 4000-pixel photo and Instagram scales it to ~1080 px and re-encodes it aggressively — two lossy steps stacked on top of each other. That's the mushy, artifact-ridden look you've seen.
The fix is to do the resize yourself, well, so Instagram has nothing left to do: upload at exactly the display size with clean encoding, and its re-compression pass has minimal impact.
The dimensions Instagram actually uses
| Placement | Ideal size | Aspect ratio |
|---|---|---|
| Feed — portrait (best reach) | 1080 × 1350 | 4:5 |
| Feed — square | 1080 × 1080 | 1:1 |
| Feed — landscape | 1080 × 566 | 1.91:1 |
| Stories / Reels cover | 1080 × 1920 | 9:16 |
| Profile picture | 320 × 320 | 1:1 |
This page presets 1080 px width and quality 88 — high enough that your file, not Instagram's re-encode, defines the look. Export in sRGB (phone photos already are).
Crop first, compress second. Crop to 4:5 or 1:1 in your photo app, then drop the result here for final sizing. Uploading odd aspect ratios forces Instagram to crop for you.