Web apps would run much better if heavy calculations could be performed in the background, rather than compete with the user interface. With this book, you’ll learn how to use Web Workers to run computationally intensive JavaScript code in a thread parallel to the UI. Yes, multi-threaded programing is complicated, but Web Workers provide a simple API that helps you be productive without the complex algorithms.

If you have an intermediate to advanced understanding of JavaScript—especially event handling and callbacks—you’re ready to tackle Web Workers with the tools in this example-driven guide.

• Start creating Web Workers and understand what they can and can’t do
• Determine which browser versions support the API
• Use dedicated Web Workers for tasks that consume a lot of CPU, such as data parsing
• Explore use cases for creating inline Workers, such as encapsulating a web app in one page
• Create a shared Worker to communicate multiple web app instances to the server, and other uses
• Learn best practices for debugging Web Workers
• Apply Web Workers within the server-side Node environment