Tags: critical

10

sparkline

The Simplest Way to Load CSS Asynchronously | Filament Group, Inc.

Scott re-examines the browser support for loading everything-but-the-critical-CSS asynchronously and finds that it might now be as straightforward as this one declaration:

<link rel="stylesheet" href="/path/to/my.css" media="print" onload="this.media='all'">

I love the fact the Filament Group are actively looking at how deprecate their loadCSS polyfill—exactly the right attitude for polyfills in general.

Going Critical — Melting Asphalt

This is an utterly fascinating interactive description of network effects, complete with Nicky Case style games. Play around with the parameters and suddenly you can see things “going viral”:

We can see similar things taking place in the landscape for ideas and inventions. Often the world isn’t ready for an idea, in which case it may be invented again and again without catching on. At the other extreme, the world may be fully primed for an invention (lots of latent demand), and so as soon as it’s born, it’s adopted by everyone. In-between are ideas that are invented in multiple places and spread locally, but not enough so that any individual version of the idea takes over the whole network all at once. In this latter category we find e.g. agriculture and writing, which were independently invented ~10 and ~3 times respectively.

Play around somewhere and you start to see why cities are where ideas have sex:

What I learned from the simulation above is that there are ideas and cultural practices that can take root and spread in a city that simply can’t spread out in the countryside. (Mathematically can’t.) These are the very same ideas and the very same kinds of people. It’s not that rural folks are e.g. “small-minded”; when exposed to one of these ideas, they’re exactly as likely to adopt it as someone in the city. Rather, it’s that the idea itself can’t go viral in the countryside because there aren’t as many connections along which it can spread.

This really is a wonderful web page! (and it’s licensed under a Creative Commons Zero licence)

We tend to think that if something’s a good idea, it will eventually reach everyone, and if something’s a bad idea, it will fizzle out. And while that’s certainly true at the extremes, in between are a bunch of ideas and practices that can only go viral in certain networks. I find this fascinating.

CSS and Network Performance – CSS Wizardry

Harry takes a look at the performance implications of loading CSS. To be clear, this is not about the performance of CSS selectors or ordering (which really doesn’t make any difference at this point), but rather it’s about the different ways of getting rid of as much render-blocking CSS as possible.

…a good rule of thumb to remember is that your page will only render as quickly as your slowest stylesheet.

The Critical Request - Speaker Deck

There are some handy performance tips from Ben in this slide deck.

In this talk we’ll study how browsers determine which requests should be made, in what order, and what prevents the browser from rendering content quickly.

The Critical Request | CSS-Tricks

Ben takes us on a journey inside the mind of a browser (Chrome in this case). It’s all about priorities when it comes to the critical path.

Calling Bullshit

A proposed syllabus for critical thinking: Calling Bullshit in the Age of Big Data.

Our aim in this course is to teach you how to think critically about the data and models that constitute evidence in the social and natural sciences.

Practical tools and case studies are also provided.

Understanding the Critical Rendering Path

A nice and clear description of how browsers parse and render web pages.

Smaller, Faster Websites - - Bocoup

The transcript of a great talk by Wilto, focusing on responsive images, inlining critical CSS, and webfont loading.

When we present users with a slow website, a loading spinner, laggy webfonts—or tell them outright that they‘re not using a website the right way—we’re breaking the fourth wall. We’ve gone so far as to invent an arbitary line between “webapp” and “website” so we could justify these decisions to ourselves: “well, but, this is a web app. It… it has… JSON. The people that can’t use the thing I built? They don’t get a say.”

We, as an industry, have nearly decided that we’re doing a great job as long as we don’t count the cases where we’re doing a terrible job.

How we make RWD sites load fast as heck

Scott shares the code that Filament Group are using to determine which style declarations are critical (and can be inlined) and which are non-critical (and can be loaded asynchronously). It makes quite a difference in perceived performance.

By the way, I really, really like the terminology of “critical” and “non-critical” CSS, rather than “above the fold” and “below the fold” CSS.

Comparing two ways to load non-critical CSS

Scott’s trying to find out the best ways to load critical CSS first and non-critical CSS later. Good discussion ensues.