Compress Images for Instagram — Free, Fast & Private
Every photo you post goes through Instagram's own encoder, and it is not gentle: anything wider than 1080px is downscaled, then the result is re-compressed to a few hundred kilobytes whatever you uploaded. Give it a 12-megapixel camera file and it makes all of those decisions for you, quickly and badly — that is the soft, blotchy version of your photo that shows up in the feed. Resize to 1080 × 1350 (or 1080 × 1080 for a square) and get the file under 1MB first, and the re-encode has almost nothing left to throw away.
MiniPx does that resize and compress entirely in your browser — nothing is uploaded to a server, and your photo stays on your phone or laptop from start to finish.
Instagram image dimensions guide
| Image type | Dimensions | Aspect ratio | Max size |
|---|---|---|---|
| Square post | 1080 x 1080px | 1:1 | 30MB |
| Portrait post | 1080 x 1350px | 4:5 | 30MB |
| Landscape post | 1080 x 566px | 1.91:1 | 30MB |
| Story / Reel cover | 1080 x 1920px | 9:16 | 30MB |
| Profile photo | 320 x 320px | 1:1 | 30MB |
Portrait posts take up the most screen space in the feed, which means more attention on your content — and the tallest supported shape is now 3:4 (1080x1440), which also matches the profile grid's portrait tiles; the Instagram post size guide compares it against the classic 4:5 (1080x1350). If you're choosing between square and portrait, go portrait. For broader social media tips, see compress images for social media.
Why compress before uploading to Instagram?
Instagram's upload limit is 30MB, but that doesn't mean you should upload a 30MB photo. Instagram will crush it down to around 200-500KB regardless. When you start with a bloated file, Instagram's algorithm makes more aggressive decisions about what to throw away. Starting with a clean, pre-compressed file around 500KB-1MB means Instagram applies less additional compression.
Reels cover images
Reel cover images display at 1080x1920 (9:16). A good cover image should be under 1MB and in JPEG format. Use MiniPx to compress your cover, then upload it when publishing your reel. Keep text within the centre area — the top and bottom get clipped in the grid view.