On today's web, performance isn't just a nice-to-have—it's essential. A slow or unstable experience drives users away, while a fast, reliable one builds trust and keeps them engaged. Web Performance Engineering in the Age of AI is a comprehensive, hands-on guide for developers, technical leads, and performance engineers focused on delivering high-impact, user-first web experiences. Written by Addy Osmani, director at Google Cloud AI, this book combines deep technical insight with a strong emphasis on usability and real-world effectiveness.

Through case studies, modern optimization techniques, and a user-centered approach, you'll learn how to identify bottlenecks, debug performance issues, and apply improvements that make a measurable difference. Grounded in current browser internals and performance metrics, this book prepares you to design and maintain faster, more resilient websites at scale.

• Understand how users perceive speed—and why it matters
• Evaluate and improve performance using key metrics
• Optimize for stability, responsiveness, and load time
• Identify and address the most common performance bottlenecks
• Apply real-world strategies that lead to lasting results

From the Preface

On today’s web, the difference between a fluid, delightful experience and a frustrating, abandoned one often comes down to milliseconds. Performance is not just a technical metric; it is the bedrock of user satisfaction and business success. At the same time, AI-assisted tools have changed how we design, build, and ship those experiences. We can now generate production-ready frontends or entire apps in minutes, but their performance characteristics still live in the real constraints of browsers, devices, and networks. Web Performance Engineering in the Age of AI is a comprehensive guide for engineers and technical leaders who need to deliver fast, responsive, and resilient web experiences in this AI-accelerated era. I’m Addy Osmani, an engineering leader on Google Chrome’s web performance team, and in this book I’ve encapsulated the latest techniques, metrics, browser internals, and AI-aware practices that define modern performance work.

Who Should Read This Book?

This book is for frontend developers, web performance engineers, and technical decision-makers who understand the basics of building websites and are driven to create experiences users love by mastering performance optimization. Whether you already lean on tools like Cursor, GitHub Copilot, ChatGPT, Gemini or other LLM-based assistants for day-to-day coding, or are just beginning to bring AI into your workflow, the goal is to help you ship experiences that stay fast and robust regardless of how the code was written. We assume you have some familiarity with HTML, CSS, and JavaScript. From there, we dive deep into the principles and practices required to build and maintain high-performing web applications, including the new realities of AI-generated and AI-augmented code.