The Right Image Size for Every Social Platform
"Just make it small" is the wrong instinct for social media — every major platform recompresses your upload anyway, so a pre-shrunk, low-quality image just gets compressed twice. What actually matters is dimensions and starting quality, not hitting the smallest possible file size yourself.
Why platforms recompress your image regardless
Instagram, LinkedIn, X and Facebook all re-encode every image you upload to their own storage format and size tiers, to keep their own bandwidth and storage costs predictable. This means your carefully-tuned file size gets discarded the moment it uploads — what survives is the pixel dimensions and the visual quality you started with.
Dimension guidance by platform
Exact numbers shift as platforms update their apps, so treat these as the right order of magnitude rather than a permanent spec:
- Instagram feed post: roughly 1080px on the long edge, square (1:1) or portrait (4:5) aspect ratio performs best in-feed
- LinkedIn feed image: roughly 1200×627px for link previews, up to 1200×1200px for standalone images
- X (Twitter) image: roughly 1200×675px (16:9) for in-feed display without cropping
- Facebook feed image: roughly 1200×630px, similar to LinkedIn
- Email: no platform recompression to rely on — compress to an actual target size (100-300KB per image is a reasonable range) since email clients don't optimize images for you
What actually matters more than exact pixel counts
Uploading an image far larger than the platform's display size wastes your upload bandwidth for zero visual benefit — the platform downscales it anyway. Uploading one far smaller than needed gets upscaled and looks soft. Landing within roughly the right range, at good starting quality (avoid re-uploading an image that's already been through several compression passes), matters more than hitting an exact number.