You Don’t Know JS Yet (book series) - 2nd Edition
This is a series of books diving deep into the core mechanisms of the JavaScript language. This is the second edition of the widely acclaimed book series.To read more about the motivations and perspective behind this book series, check out the Preface.
Book Titles
I recommend reading the second edition books in this order:Get Started
The foundational book that introduces you to JavaScript’s core concepts and gets you started on your journey.
Scope & Closures
Deep dive into lexical scope, function vs. block scope, hoisting, and closure patterns.
Objects & Classes
Explore prototypes, object patterns, and the class system (draft stable).
Types & Grammar
Understanding JavaScript’s type system and language grammar (rough draft).
Purchase Options
All books are available through:“The Unbooks” is an ebook collection that includes Objects & Classes and Types & Grammar.
Free & Open Source
As always, you’ll be able to read these books online here entirely for free. This edition of the books is being self-published through GetiPub publishing. The published books are also made available for sale through normal book retail sources.Support the Author
If you’d like to contribute financially towards the effort (or any of Kyle Simpson’s other OSS efforts) aside from purchasing the published books, please consider these options:GitHub Sponsors
Support through GitHub Sponsorship
Patreon
Become a patron
PayPal
One-time contribution
Contributions
This book series is now complete, and is not open to further contributions. Thank you to those who’ve been part of the 11 years journey of this book series.Special Thanks to Our Sponsors
Frontend Masters
The first two books of the second edition are exclusively sponsored by Frontend Masters.Frontend Masters is the gold standard for top-of-the-line expert training material in frontend-oriented software development. With over 150 courses on all things frontend, this should be your first and only stop for quality video training on HTML, CSS, JS, and related technologies.
Kyle Simpson teaches all his workshops exclusively through Frontend Masters. If you like this book content, please check out his video training courses.
License & Copyright
The materials herein are all © 2019-2025 Kyle Simpson. This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 4.0 Unported License.