Complete Guide to Web Image Formats: JPG vs PNG vs WebP vs AVIF

## Choosing the Best Image Format for Web Performance Images make up more than 60% of the average webpage's total byte weight. Choosing the correct image format directly impacts your Google Core Web Vitals, user engagement, and SEO rankings. ### 1. JPEG (JPG): The Universal Standard JPEG has been the dominant image format on the web for over three decades. It uses lossy DCT compression and is ideally suited for complex photographs with smooth gradients and millions of colors. ### 2. PNG: The Standard for Transparency Portable Network Graphics (PNG) is a lossless bitmap format designed to replace GIF. It is indispensable for logos, charts, illustrations, and user interface screenshots requiring transparent backgrounds. ### 3. WebP: The Modern Web Workhorse Developed by Google, WebP offers both lossy and lossless compression. WebP files are typically **25% to 35% smaller than comparable JPEGs** and **up to 50% smaller than PNGs** while fully supporting alpha transparency. ### 4. AVIF: The Next-Generation Format AVIF is an open, royalty-free format derived from the AV1 video codec. It provides extraordinary compression efficiency—often cutting file sizes by an additional 20% to 30% compared to WebP at equivalent visual quality.