Image Optimization

Images have always been a key part of the web. Our brains are able to interpret images much faster than text, which is why high-quality visuals drive conversions and user engagement.



That said, loading images efficiently at scale isn’t a little project for a quiet afternoon. It requires understanding of compression techniques, loading behavior, image decoding and image CDNs, adaptive media loading and caching.



This book will equip you with everything you need to know to optimize how you compress, serve and maintain images — boosting performance along the way.



About the Book



Next to videos, images are the heaviest, most requested assets on the web. Some of the biggest size savings and performance improvements can come through a better image optimization strategy. The fewer bytes a browser has to fetch, the less competition there is for a user’s bandwidth, and the quicker that critical image can be displayed, along with page’s content.



With the new Smashing book, Addy Osmani provides a practical modern guide to delivering high-quality images on the web — from formats and compression to delivery and maintenance.



The book focuses on what matters: modern approaches to image compression and image delivery, practical tools and techniques to automate optimization, responsive images, current and emerging image formats, how browsers load, decode and render images, CDNs, lazy-loading, adaptive media loading and how to optimize for Core Web Vitals. Everything in one, single, 528-pages book.



Written by Addy Osmani. Illustrated by Espen Brunborg and Nadia Snopek. Reviewers and contributors include Milica Mihajlija, Colin Bendell, Kornel Lesiński, Estelle Weyl, Jeremy Wagner, Tim Kadlec, Nolan O’Brien, Pat Meenan, Kristofer Baxter, Henri (Helvetica) Brisard, Houssein Djirdeh, Una Kravets, Ilya Grigorik, Elle Osmani, Leena Sohoni, Katie Hempenius, Jon Sneyers, and Mathias Bynens.



Table of Contents



1.The Humble Element

2.Optimizing Image Quality

3.Comparing Image Formats

4.Color Management

5.Image Decoding Performance

6.Measuring Image Performance

7.JPEG

8.PNG

9.WebP

10.SVG

11.Responsive Images

12.Progressive Rendering Techniques

13.Optimizing Network Requests with Caching and Preloading

14.Lazy-Loading Offscreen Images

15.Replacing Animated GIFs

16.Image Content Delivery Networks

17.HEIF and HEIC

18.AVIF

19.JPEG XL

20.Comparing New Image File Formats

21.Delivering Light Media Experiences with Data Saver

22.Optimize Images for Core Web Vitals

23.Twitter’s Image Pipeline (Case Study)