Going Offline

As you’ve probably gathered if you’ve been following my work for the last few years, I’m super-jazzed about Progressive Web Apps. I think they have the potential to improve user experience, performance, access, and so much more for so many people. So I was stoked when Jeremy Keith asked me to write the foreword for his latest book, Going Offline, which tackles the complex topic of Service Workers with aplomb.

With his permission (and A Book Apart’s), I’m reprinting the foreword here.

We often talk gleefully about the open and ubiquitous nature of the web, but it has an Achilles’ heel: network connectivity. If your career is spent working on the web, chances are you might rarely encounter networking issues in your day-to-day life. When it comes to networks, many of us are spoiled with sweet, sweet speed and incredible reliability. We take it for granted that everyone in the world experiences the web like we do.

With an uncertain network connection, the web can be elusive. Broken page layouts. Missing functionality. Lost images. Dinosaurs. Broken hearts. Frustration.

With no network at all, the web ceases to exist.

Over the years, scores of people far smarter than I have looked for ways to help the web overcome its complete dependence on the network. Browser caching, Application Cache, Local (and Session) Storage, and client-side databases have all helped to some degree (well, maybe not AppCache) but these technologies have been somewhat limited in both scope and capability.

Then along came the service workers. Service workers are one of the most powerful tools we’ve had at our disposal, enabling us to control how we handle network requests. They even enable us to decide whether to make a network request at all. Of course, that power also gives us the ability to completely break our sites—if we’re not careful.

Which brings me to the book you hold in your hands. In Going Offline, Jeremy Keith breaks down heady concepts into approachable prose and easy-to-follow code examples. He also points out service worker gotchas and shows you how to deftly avoid them. Invest a scant few hours with this book, and you’ll gain a solid understanding of how to put this new technology to work for you right away. No, really—within fifteen to twenty minutes of putting it down.

Armed with the knowledge you gain from Jeremy’s words, I have no doubt you’ll do wonders to improve the resilience of the web.

—Aaron Gustafson

You can (and should) purchase Going Offline directly from A Book Apart. You can also read Chapter 1 of Going Offline on A List Apart.



  1. @rem
  2. Dmitri Kunin
  3. Ahn