How to prepare an image for social media
Square 1080×1080 for an Instagram feed post, 1080×1350 for portrait, 1080×1920 for stories and reels. 1200×630 for a link preview on any platform. Export as JPG or WebP at 85% — every platform re-compresses what you upload, so uploading a huge PNG only means their encoder, not yours, decides how it degrades.
The sizes, and the one that is not obvious
Feed and profile images are straightforward: square at 1080, portrait at 1080×1350, vertical video and stories at 1080×1920. Avatars are square and small, so check that your logo is still readable at 100 pixels.
The non-obvious one is 1200×630, the Open Graph card that appears when someone shares a link. It is not an Instagram size, it is the size every platform crops a shared URL preview to, and getting it wrong is why a shared link sometimes shows a strangely cropped image.
Why your upload looks worse than your file
Every platform re-encodes uploads to its own specification, and it does so from whatever you gave it. Upload a 6000-pixel image for a 1080-pixel slot and their downscaler, tuned for speed, makes that decision instead of you.
Resize to the target size yourself and export at 85% quality. The result survives the platform’s second pass noticeably better than a file that arrives oversized.
Making a landscape photo square
Two choices: crop to fill, which loses the edges, or pad to a square, which keeps everything and adds colour at the sides. For products and graphics, pad — cropping a product in half is worse than a visible margin. For scenes and portraits, crop.