Web Performance: How Image Optimization Improves Core Web Vitals

Images account for 50% of page weight. Here's how image compression directly impacts Google's Core Web Vitals and your search rankings.

The Problem: Slow Images Kill SEO

Google's research shows that a 1-second delay in page load reduces conversions by 7%. Images are the #1 cause of slow Largest Contentful Paint (LCP) β€” a Core Web Vital that directly affects rankings.

Image Format Impact on Page Speed

Step-by-Step: Optimize Images for Web

Common Mistakes

FormatFile Size (photo)TransparencyAnimationBest For
JPEGSmallNoNoPhotographs
PNGLargeYesNoLogos, graphics
WebPSmallestYesYesModern browsers (95%+)
AVIFVery smallYesYesCutting edge (80%+)
SVGN/A (vector)YesYesIcons, logos

Frequently Asked Questions

How does image compression affect SEO?

Compressed images load faster, improving Largest Contentful Paint (LCP) β€” one of Google's three Core Web Vitals. Sites with good LCP scores rank higher. A 50% image size reduction can improve LCP by 1-2 seconds.

What's the ideal image file size for web?

Under 100KB for thumbnails, under 300KB for content images, under 500KB for hero images. Use WebP format for 25-35% smaller files than JPEG with the same quality.

Should I compress images before or after uploading?

Before. Server-side compression is good, but pre-compressed images load even faster. Use our browser-based compressor to reduce file size without any quality loss visible to the human eye.

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