Performance

Load non-critical resources when a user interacts with UI requiring it

A lot has changed since 2017 we I last estimated a global baseline for total page resource limits of 120-170KiB. Thanks to progress in networks and browsers (but not devices), the new baseline is much more generous: ~100KiB of HTML/CSS/fonts and ~300-350KiB of JS. But the devil's in the footnotes, and modern web development practices push the median page well above these guidelines.

La lettre de la DAJ Loi n° 2021-1755 du 23 décembre 2021 visant à renforcer la régulation environnementale du numérique par l'Autorité de régulation des communications électroniques, des postes et de la distribution de la presse (ARCEP)

GOV.UK dropped their jQuery dependency from their front end. You'll never guess what happened. (Yes, you will.)

First part of a series of blog posts that together make a coherent How-to guide on optimizing Drupal for speed.

The 512KB Club is an exclusive list of web pages weighing less than 512 kilobytes.

I've been thinking about social media images again. You know, the images that (can) show up when you share a link in places like Twitter, Facebook, or

Break HTML document size down by tag and attribute. Discover bloat like code duplication, large hydration state, and inline images.

How big are pages today vs. ten years ago? How does page bloat hurt your business? How does it affect Google's Core Web Vitals? What can you do to fight it?

Learn about how to optimize web fonts for Core Web Vitals.

Sometimes you want to share a Youtube video on your website, instead of just pasting a link. The prob...

Your may not think it, but your 404 page is an important part of your potential user journey. You should test its web performance as it can have a big impact...

HTTP cache headers can significantly improve the user experience of web applications. Understand their use and in what scenarios to employ them.

Social networks are everywhere online. Share, like and tweet buttons are popping up on a lot of webpages these days.The social buttons however have a big impact on the performance of a website. They load a ton of resources and slow down websites.In this post I'll tell you why I hate these social buttons so much. I'll also walk you through the ...

Gathering data about third-parties using free and open-source tooling

Data on third party entities and their impact on the web. - patrickhulce/third-party-web: Data on third party entities and their impact on the web.

In the spirit of reddit's /r/explainlikeimfive let me try to summarize the art and craft of web performance optimization for the uninitiated reader. The word "performance" can be misunderstood, so let's define it first. Say you have work to do. Your performance would be measured by how quickly you

While the practice of web performance has been around for a while and the ability to study and debug JavaScript (JS) errors has improved over the years, we've never really looked at the impact errors have on performance. JavaScript errors are among the more complex metrics collected by Akamai's Rea

Import any kind of server logs in Matomo for powerful log analytics. Universal log file parsing and reporting. - matomo-org/matomo-log-analytics: Import any kind of server logs in Matomo for powerf...

A tool for finding memory leaks in web apps. Contribute to nolanlawson/fuite development by creating an account on GitHub.

How browsers schedule and execute scripts can impact the performance of web pages. While techniques like script defer, link rel=preload (and ...

Patrick Stox explains how page speed works, and what actions to take for your site.

Image optimization is hard and automation is the key to success.

Web Workers are a simple means for web content to run scripts in background threads. The worker thread can perform tasks without interfering with the user interface. In addition, they can perform I/O using XMLHttpRequest (although the responseXML and channel attributes are always null) or fetch (with no such restrictions). Once created, a worker can send messages to the JavaScript code that created it by posting messages to an event handler specified by that code (and vice versa).

Priority Hints provide developers a way to indicate a resource's relative importance to the browser, allowing more control over the order resources are loaded.

Responsive landing page hero videos are increasingly popular, here we show how to make them as fast as possible.

Check if your site meets the Core Web Vitals assessment in one click.

I recently gave a talk on “Making Sense of Performance Metrics” at the Web Unleashed Conference, and it was suggested that I turn the breakdown of all the performance metrics into a cheatsheet; so here it is! The full cheatsheet, including a downloadable PDF version, are at the bottom of