You-Dont-Know-JS 0,37,190,0,43,78,0,187

A book series on JavaScript. @YDKJS on twitter.

You Don’t Know JS (book series)

This is a series of books diving deep into the core mechanisms of the JavaScript language. The first edition of the series is now complete.


Please feel free to contribute to the quality of this content by submitting PR’s for improvements to code snippets, explanations, etc. While typo fixes are welcomed, they will likely be caught through normal editing processes, and are thus not necessarily as important for this repository.

To read more about the motivations and perspective behind this book series, check out the Preface.



These books are being released here as drafts, free to read, but are also being edited, produced, and published through O’Reilly.

If you like the content you find here, and want to support more content like it, please purchase the books once they are available for sale, through your normal book sources. :)

If you’d like to contribute financially towards the effort (or any of my other OSS work) aside from purchasing the books, I do have a patreon that I would always appreciate your generosity towards.


In-person Training

The content for these books derives heavily from a series of training materials I teach professionally (in both public and private-corporate workshop format), called “Advanced JS: The ‘What You Need To Know’ Parts”.

If you like this content and would like to contact me regarding conducting training on these, or other various JS/HTML5/node.js topics, please reach out to me through any of these channels listed here:

Online Video Training

I also have some JS training material available in on-demand video format. I teach courses through Frontend Masters, like my Advanced JS workshop (more courses coming soon!).

That same course is also available through Pluralsight.


Any contributions you make to this effort are of course greatly appreciated.

But PLEASE read the Contributions Guidelines carefully before submitting a PR.

License & Copyright

The materials herein are all © 2013-2016 Kyle Simpson.

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 4.0 Unported License.

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