Mastering Image Compression & Next-Gen Formats for 100/100 PageSpeed

Introduction: The Primary Bottleneck of Modern Websites

According to the HTTP Archive Web Almanac, images comprise more than 60% of the median total byte weight of web pages. When non-technical publishers upload raw 4MB camera captures or 24-bit PNG screenshots directly into blog posts, the consequences are severe: slow mobile loading, frustrated users abandoning the site, and poor Largest Contentful Paint (LCP) audit scores from Google Lighthouse.

Understanding Google's Core Web Vitals Benchmark

Google's ranking algorithm assesses page speed via three Core Web Vitals metrics:

• LCP (Largest Contentful Paint): Measures how quickly the main visual element (typically the hero banner or featured image) becomes visible. To earn a "Good" rating, LCP must occur in under 2.5 seconds.
• CLS (Cumulative Layout Shift): Measures visual stability as elements load. Always define explicit width and height attributes on images to prevent content shifts.
• INP (Interaction to Next Paint): Replaces FID, measuring overall responsiveness to user taps and clicks.

Format Comparison: WebP vs AVIF vs JPEG