WebP is a modern image format developed by Google that typically reduces file size by 25–35% compared to JPEG for photos and by a similar margin compared to PNG for graphics with transparency. Smaller images improve page load speed and positively influence [Core Web Vitals](/glossary/core-web-vitals), particularly [Largest Contentful Paint (LCP)](/glossary/lcp). WebP is supported by all major browsers and is often the default output of image optimisation pipelines. For environments where even smaller files are needed, AVIF is a newer alternative that compresses further, with WebP served as a fallback.