Josh W Comeau homepage

Unraveling the mystery of percentage-based heights in CSS

One of the most perplexing and befuddling things in CSS for me, for many years, was the behaviour of percentage-based heights. Sometimes, seemingly at random, setting “height: 100%” would have no effect at all. When I finally figured out what was going on, it was like a puzzle piece snapping into place; everything made so much more sense! In this post, I’ll share the epiphany I had, and we’ll explore some solutions.

When OpenAI released GPT-4 back in March 2023, they kickstarted the AI revolution. The consensus online was that front-end development jobs would be totally eliminated within a year or two.Well, it’s been more than two years since then, and I thought it was worth revisiting some of those early predictions, and seeing if we can glean any insights about where things are headed.

Deconstructing the “Whimsical Animations” landing page

I spent the past few weeks packing as many easter eggs as I could into my latest project, and in this blog post, I want to dig into some of the more interesting details! If you’re interested in animations/interactions, you’ll want to check this one out; I share a bunch of my favourite secrets and tricks. 😄

Container queries expand the universe of designs that can be implemented, giving us whole new superpowers. Now that container queries are broadly available, I think it’s time we start exploring this potential! In this post, I’ll share the “killer pattern” I can’t stop using in my work, and explore what’s possible with this new capability.

Glassy headers have become a core part of the “slick startup” UI toolkit, but they’re all missing that final 10% that really makes it shine. In this tutorial, you’ll learn how to create the most realistic lush frosted glass anywhere on the internet.

Lots of exciting new features have been landing in CSS recently, and it can be tough trying to figure out if they’re safe to use or not. We might know that a feature is available for 92% of users, but is that sufficient? Where do we draw the line? In this blog post, I’ll share the framework I use for deciding whether or not to use a modern CSS feature

It’s been a couple of years since container queries started landing in browsers… so why isn’t anyone using them? It turns out that container queries are kinda tricky; they’re not as straightforward as media queries. In this tutorial, we’ll break it all down and make sense of them, so that you can start using them in your work.

2024 “App Router” Edition

I recently launched a brand new version of this blog, and in this post, I share how it’s built! We’ll examine the tech stack and see how all of the pieces fit together, as well as dig into some of the details to see how they work.

Of all the latest and greatest CSS features, the “:has” pseudo-class wasn’t exactly at the top of my wishlist. Once I started using it, however, I kept discovering incredible things I could do with it. It’s now become a core part of my toolkit! In this blog post, I'll show you some practical real-world problems I solved using “:has”, as well as some wild experiments that blew my mind!

The “Promises” API is a surprisingly tricky part of modern JavaScript. Without the right context, it doesn’t make much sense at all! In this tutorial, you’ll build an intuition for how Promises work by getting a deeper understanding of JavaScript and its limitations.

useDeferredValue is one of the most underrated React hooks. It allows us to dramatically improve the performance of our applications in certain contexts. I recently used it to solve a gnarly performance problem on this blog, and in this tutorial, I'll show you how! ⚡

Understanding the future of CSS-in-JS and React

You can’t make an omelette without cracking a few eggs, and when the core React team unveiled their vision for the future of React, some of my favourite libraries got scrambled 😅. In this blog post, we’re going to explore the compatibility issues between React Server Components and CSS-in-JS libraries like styled-components. You’ll understand what the issue is, what the options are, and what’s on the horizon.