Social Media Image Size Guide 2026

Every platform has its own sizes, but four principles work across all of them:

1. Upload at native resolution, not smaller. Downscaling produces sharp results. Upscaling produces blur. Always upload at the platform's recommended size or a 2x multiple, never below.
2. Use JPEG at 90%+ quality. Every platform converts to JPEG anyway. Starting from a high-quality JPEG gives the re-encoding more to work with. PNG only when transparency or sharp text edges matter.
3. Keep important content in the central 70-80%. Every platform crops differently on mobile vs desktop, or in different feed contexts. The center always survives.
4. Test at the smallest display size. If your design reads at 48 × 48 pixels (typical mobile timeline avatar), it works everywhere. If it requires the full 400 × 400 to be understood, redesign for legibility at small sizes.

Every social platform applies its own image re-encoding pipeline regardless of how you uploaded. Instagram, Facebook, X, LinkedIn, YouTube, Discord, Etsy - all of them. The reasons are bandwidth and storage cost: serving a 5 MB original to every viewer would cost the platform millions per day in CDN fees.

The platform-side re-encoding is typically JPEG at 75-85% quality, with the original re-saved at multiple resolutions for different display contexts (thumbnail, mobile, desktop, retina). Your high-quality source becomes the seed material for all these resampled versions.

Practical consequence: a heavily compressed source becomes a more heavily compressed served version. A high-quality source becomes a moderately compressed served version. The visible difference is significant on text-heavy and high-contrast images. For photographs of natural scenes, the difference is barely noticeable. Always start from high quality and let the platform do its own compression.