Why JPG Size Matters

  • Oversized JPGs tank LCP scores and mobile user experience
  • Small JPGs save CDN bandwidth costs on high-traffic sites
  • Properly sized JPGs render faster on retina vs non-retina displays
  • Email JPGs must fit under 25 MB Gmail and Outlook attachment limits

JPG Resizing Best Practices

  • Downscale to the exact display size — never ship 4000px JPG for a 600px container
  • Keep aspect ratio locked unless a crop is specifically wanted
  • Use 2× resolution for JPG destined for retina displays (Instagram, web hero)
  • Avoid upscaling JPGs — you can't invent detail that isn't in the source
  • Pair resize with compression for maximum file-size reduction