⚡ WebAssembly the practical way

A practical book for web developers looking to get started with WebAssembly, even if you don't know any C or C++.
Updated May 2020
Book cover image

What you'll learn

Forget toy examples; learn to compile real-world software to WebAssembly.


Port C/C++ tools to the browser, including jq, awk, and coreutils.


Port games like Pong, Tetris, and Pacman to the web.

Run WebAssembly on the cloud, in serverless functions.

Run WebAssembly modules in threads using WebWorkers.


Process user files in your apps using virtual file systems.


Recognize use cases where WebAssembly shines.

Buy the book

Not convinced? Check out a book sample
or the table of contents.

What readers think of the book

WebAssembly is constantly evolving and it can be hard to find concise and up-to-date information to learn how to wield its awesomeness. Level Up with WebAssembly was the tl;dr I was looking for.

Jonathan Beri

When I joined the Chrome WebAssembly team as their Product Manager and needed to get up to speed on using WebAssembly, I used this book. I had a complex codebase that I wanted to bring to the web and I directly used the examples in this book to successfully accomplish the port.

Thomas Nattestad

The book is concise, example-packed, and implementation-oriented. The book shows approaches that have worked but also those that have failed, possibly saving developers time by avoiding dead ends.

A sneak peek of what you'll build:

My personal favorite is porting a C++ Pacman clone to the browser:

Porting Pacman to the web

Port command-line tools like diff, and use them in your web apps!
(included in the Complete Edition package)

Porting the diff command-line utility to the web

In the Capstone project, you'll build a web app that
clusters data points, and plots the results interactively:
(included in the Complete Edition package)

Porting the KMeans algorithm with WebAssembly

How deep do you want to go?

The Book

The Minimalist



  • Updated May 2020
    The Book
    PDF with ~100 pages, jam-packed with WebAssembly awesomeness. All future updates to the book included.
Buy for $29

The Starter Kit

Hit the Ground Running


  • Includes The Book plus:

  • new august 2019
    Serverless WebAssembly
    A guide to serverless WebAssembly. Includes code + deploy instructions for AWS, GCP, Azure, Cloudflare & Fastly.

  • Cheat Sheet
    Cheat Sheets
    The most common command-line options you'll need for Emscripten + reference code snippets.

  • Guide
    Quickstart Guide to WebWorkers and FileReader
    Guide to two Web APIs used in the book to complement WebAssembly.
Buy for $49

The Complete Edition

Everything But the Kitchen Sink


  • Includes Starter Kit plus:

  • Guide
    Guide to Porting UNIX
    tools to the web

    Learn to port awk, diff and coreutils tools such as cut, sort and uniq!

  • Capstone
    Capstone Project
    Practice what you learned: build an interactive web tool that uses WebAssembly to cluster data points.

  • Screencasts
    15 Command-Line Screencasts
    With play/pause controls and copy/paste functionality.
Buy for $129

See team discounts here.