Now THAT’S What I Call Service Worker!

If you’re looking to achieve the single-page app level performance without the overhead (and boot time) of a huge JavaScript library or having to completely rewrite your website in a new technology, Jeremy Wagner shares a clever approach combining Service Worker and streamed web page partials you’re sure to love.

Request with Intent: Caching Strategies in the Age of PWAs

Caching media files, especially images, seems like an obvious way to improve performance, but should we? To provide a more performant UX without abusing users’s network connections or hard drives, Aaron Gustafson puts a spin on classic best practices, experiments with media caching strategies, and shares smart Cache API tricks.

Responsible JavaScript: Part II

Web development is hard. We don’t always get it right on the first try. Fortunately, we don’t have to get everything perfect from the start. Jeremy Wagner provides some helpful ways to start recovering from our collective JavaScript hangover.

Semantics to Screen Readers

As an extension to our From URL to Interactive series, designer and front-end developer Melanie Richards takes a deep dive into how our content is accessed by a wide array of screen readers, which are highly customizable to users. Understanding the nuances of accessibility APIs, thorough testing approaches, and the wealth of resources available, site creators can create the most widely accessible content for the most users possible.

var to JIT

JavaScript language designer Kevin Smith completes the “From URL to Interactive” series. He explains how browsers compile and execute our JavaScript, and what happens from the moment we land on the page to when we leave. Understanding these browser processes leads us to write more performant code.

Braces to Pixels

We continue on A List Apart’s four-part “From URL to Interactive” series with Greg Whitworth, a member of the W3C CSS Working Group and the CSS Houdini Task Force. He’ll walk through how CSS is parsed, how values are computed, and what the “cascade” in style sheets actually means. Then we’ll discuss layout, painting, and composition. Brace yourselves, we’re about to drive through a one of our most scenic and winding parts of our journey.

Tags to DOM

In the second installment of A List Apart’s four-part “From URL to Interactive” series, Travis Leithead, former editor of W3C’s HTML spec, walks us through the process of parsing HTML: from how browsers create trees to how the DOM responds to events. Equipped with this knowledge, you’ll be able to make smarter DOM decisions, reduce time to interactive, and eliminate unintended reflows.

From URL to Interactive

When we think about it, our whole industry depends on our faith in a handful of “black boxes” few of us fully understand: browsers. We hand over our HTML, CSS, JavaScript, cross our fingers, and hope they render the experience we have in our heads. But knowing how they work can really get you out of a jam when things go wrong. That’s why we’ve assembled a handful of incredibly knowledgeable authors to take us under the hood in this four-part series. Join us on this trip across the web, into the often foggy valley between code and experience.

Server to Client

Kicking off the first installment in our “From URL to Interactive” series, Ali Alabbas takes us through the journey of how our code makes it to the browser. In “Server to Client”, he discusses how server connections are made, caching, and how service workers factor into the request and response process. You don’t want to miss this master class from a networking expert; grasping this aspect of how things run under the browser hood is essential to understanding performance.

Responsive Images

The `img` element remains one of the biggest challenges for website performance, especially in responsive designs. In this excerpt from Image Performance, Mat Marquis tells us why, but he also shines a light on the solution.