Web Performance Fundamentals: A Frontend Developer’s Guide to Profile and Optimize React Web Apps

Get the practical tools and techniques you need to make your React apps faster, smoother, and more efficient.

Throughout the book, you’ll follow a clear, hands-on path that mirrors the real performance journey of a modern web app. We'll start by understanding why speed matters (and how to measure it), then explore initial-load performance and why it's so critical for a first impression. In the process, we’ll turn performance Flame Graphs from an incomprehensible mess into relaxed bedtime reading, gain a deep understanding of every render pattern (CSR, SSR, RSC, etc.), and learn how to measure the impact of each one.

The bundle-size investigation will let you play detective, discovering the different uses of Suspense will make you an explorer, and uncovering the purpose of React Server Components will set you on an adventurer’s path - with performance treasures as your reward.

We'll finish with a solid understanding of interaction performance, revisit the role re-renders play in it, and take a look at the React Compiler.

All of this while tinkering with a complex, multi-page study project and experimenting with various build tools and frameworks (Vite, TanStack, and Next.js).

I'm new to React. Is this book a good fit for me?

If you're still learning the basics of React, this book might be a bit too advanced for you right now. It's written for developers who are comfortable navigating a React codebase, have a solid understanding of core React concepts, and want to deepen their skills by exploring the specifics of web performance.

That said, much of the book isn't React-specific. About two-thirds of it covers general web performance topics that apply to any web app, regardless of the framework. So if you're comfortable with the basics of web development and want to learn more about performance, you'll still find it useful.