Serving images in the right format, from a CDN, with the right HTML can be a big performance win.

Time to First Byte (TTFB) is crucial, but improving it requires more than tweaking server response time.

What is this “main thread” we’re talking about? Where does it come from? And why not multiple threads?

Building for scale involves creating systems that can handle increased loads, adapt to changing demands, and operate seamlessly.

The popover drama started with a tweet about how a HEY Calendar popover loaded slowly on a throttled internet connection.

Apple’s WebKit team is excited to introduce Speedometer 3.0, a major update that better reflects the Web of today.

What is the average size of JavaScript code downloaded per website? Let's find out!

Late last year, I had an idea that’s been steadily brewing in my head.

Cumulative Layout Shift (CLS) is one of the Core Web Vital performance metrics.

Web performance can be pretty tricky. I mention this so you don’t get demoralized if you hit a wall or struggle to identify an issue.

Starting in March 2024, Interaction to Next Paint will formally replace First Input Delay as a Core Web Vital metric.

We know we should do it, but do we know how?

Can Low-Quality Image Placeholders and LCP play nicely together?

I see a recurring performance problem on many ecommerce sites—the most important images on the page are being lazy loaded when they shouldn’t be.

How Liran Cohen and the team at Bookaway, a travel booking service, dramatically improved their site’s performance.

There’s still a lot of misunderstanding about CWV for SEO. Let’s work it out together.

As web applications grow larger, they inevitably fall prey to complexity, despite our best intentions.

How two simple steps improved the responsiveness of Wikipedia’s mobile site.

A look at how different web frameworks perform in the real world in 2023.

New web services are being built to a self-defeatingly low UX and performance standard.