Image Optimization

Image optimization balances visual quality with file size to deliver compelling imagery without compromising page performance or user experience, often representing the largest opportunity for page speed improvement on media-rich sites. Our comprehensive image optimization guides cover every technique for reducing image impact on load times while maintaining the visual quality your content requires to engage visitors. You will learn format selection strategies that choose the right format for each image type, understanding the tradeoffs between JPEG, PNG, WebP, AVIF, and emerging formats in terms of quality, file size, and browser support. We explore compression techniques that dramatically reduce file sizes with minimal visible quality loss, using appropriate tools and settings for different image types including photos, graphics, and screenshots that require different approaches. Our guides cover responsive images that serve appropriately sized files to different devices using srcset and sizes attributes, avoiding wasteful delivery of large images to small screens that costs bandwidth and performance. You will learn lazy loading implementation that defers loading of images outside the initial viewport, improving perceived performance and initial load times without affecting user experience for images they will eventually view. We address image dimensions and layout considerations that prevent Cumulative Layout Shift, ensuring images do not cause visual instability as pages load through proper width and height attributes or aspect ratio techniques. Our resources cover image delivery optimization including CDN configuration for images, next-gen format delivery based on browser support using picture elements or content negotiation, and caching strategies that reduce repeat visitors' load times. You will learn to audit and prioritize image optimization opportunities across your site, identifying the images with largest impact. These guides help you achieve the performance benefits of optimized images throughout your entire site.