Tags: loading

How To Improve Largest Contentful Paint for Faster Load Times - Calibre

A no-nonsense checklist of good performance advice from Karolina.

In Defence of the Single Page Application | William Kennedy

This is very convincing.

Picture perfect images with the modern img element - Stack Overflow Blog

Addy takes a deep dive into making sure your images are performant. There’s a lot to cover here—that’s why I ended up splitting it in two for the responsive design course: one module on responsive images and one on the picture element.

[css-fonts-5] @font-face supports incremental · Issue #6063 · w3c/csswg-drafts

This could give a big boost to web performance!

Conditional JavaScript - JavaScript - Dev Tips

This is a good round-up of APIs you can use to decide if and how much JavaScript to load. I might look into using storage.estimate() in service workers to figure out how much gets pre-cached.

AddyOsmani.com - Preload late-discovered Hero images faster

Did you know there’s an imagesrcset attribute you can put on link rel="preload" as="image" (along with an imagesizes attribute)?

I didn’t. (Until Amber pointed this out.)

AVIF has landed - JakeArchibald.com

There’s a new image format on the browser block and it’s very performant indeed. Jake has all the details you didn’t ask for.

The beauty of progressive enhancement - Manuel Matuzović

Progressive Enhancement allows us to use the latest and greatest features HTML, CSS and JavaScript offer us, by providing a basic, but robust foundation for all.

Some great practical examples of progressive enhancement on one website:

• using grid layout in CSS,
• using type="module" to enhance a form with JavaScript,
• using the picture element to provide webp images in HTML.

All of those enhancements work great in modern browsers, but the underlying functionality is still available to a browser like Opera Mini on a feature phone.

Scripts: async, defer

I’m constantly forgetting the difference between the async attribute and the defer attribute on script elements—this is a handy explanation.

Page Speed Benchmarks | SpeedCurve

This is going to be so useful for client work at Clearleft—instant snapshots of performance metrics across industries and regions!

For example, we’ve been working a lot with the travel sector, and now we can call up these benchmarks without having to generate a whole bunch of Web Page Test results ourselves.

See Tammy’s blog post for me details.

Move Fast & Don’t Break Things | Filament Group, Inc.

This is the transcript of a brilliant presentation by Scott—read the whole thing! It starts with a much-needed history lesson that gets to where we are now with the dismal state of performance on the web, and then gives a whole truckload of handy tips and tricks for improving performance when it comes to styles, scripts, images, fonts, and just about everything on the front end.

Essential!

Request with Intent: Caching Strategies in the Age of PWAs – A List Apart

Aaron outlines some sensible strategies for serving up images, including using the Cache API from your service worker script.

How Web Content Can Affect Power Usage | WebKit

The way you build web pages—using IntersectionObserver, for example—can have a direct effect on the climate emergency.

Webpages can be good citizens of battery life.

It’s important to measure the battery impact in Web Inspector and drive those costs down.

Paint Holding - reducing the flash of white on same-origin navigations  |  Web  |  Google Developers

This is an excellent UX improvement in Chrome. For sites like The Session, where page loads are blazingly fast, this really makes them feel like single page apps.

Our goal with this work was for navigations in Chrome between two pages that are of the same origin to be seamless and thus deliver a fast default navigation experience with no flashes of white/solid-color background between old and new content.

This is exactly the kind of area where browsers can innovate and compete on the UX of the browser itself, rather than trying to compete on proprietary additions to what’s being rendered.

Redux: Lazy loading youtube embeds

Remy has an excellent improvement on that article I linked to yesterday on using srcdoc with iframes. Rather than using srcdoc instead of src, you can use srcdoc as well as src. That way you can support older browsers too!

Lazy load embedded YouTube videos - DEV Community 👩‍💻👨‍💻

This is a clever use of the srcdoc attribute on iframes.

Native lazy-loading for the web  |  web.dev

The title is somewhat misleading—currently it’s about native lazy-loading for Chrome, which is not (yet) the web.

I’ve just been adding loading="lazy" to most of the iframes and many of the images on adactio.com, and it’s working a treat …in Chrome.

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.

The Crushing Weight of the Facepile—zachleat.com

Using IntersectionObserver to lazy load images—very handy for webmention avatars.

Test the impact of ads and third party scripts

This is a very useful new feature in Calibre, the performance monitoring tool. Now you can get data about just how much third-party scripts are affecting your site’s performance:

The best way of circumventing fear and anxiety around third party script performance is to capture metrics that clearly articulate their performance impact.