Brotli is gaining steam as the compression algorithm du jour for high performance websites. Created back in 2013 by Google to decrease the size of WOFF files, Brotli was standardized in 2016 as part of RFC 7932. The sales pitch for Brotli is better compression than Gzip - with similar CPU usage. Better compression leads to faster performance, but how much better is it?

HTTP/3 is here, and it’s a big deal for web performance. See just how much faster it makes websites! Wait, wait, wait, what happened to HTTP/2? Wasn’t that all the rage only a few short years ago? It sure was, but there were some problems. To address them, there’s a new version of the venerable protocol working its way through the standards track. Ok, but does HTTP/3 actually make things faster? It sure does, and we’ve got the benchmarks to prove it.

The fastest website is the website that is already loaded, and that’s exactly what we can do with HTTP caching. HTTP caching lets web browsers reuse of previously loaded resources, like pages, images, JavaScript, and CSS. It’s a powerful tool to improve your web performance, but misconfiguration can cause big performance problems. Here’s what you need to know to use HTTP caching without reading hundreds of pages of HTTP Caching Spec.

Synthetic Testing and Real User Monitoring are the most important tools in your performance toolbox. But they do different things and are useful at different times and many developers only spend time mastering one of these tools and only see a part of their performance problems, like trying to hammer in a screw. Let’s look at these tools, what they measure, and when to use them.

Advertising is everywhere on the web and users have noticed. More than 40% of internet users block ads. Are these users sticking it to the man or just tired of slow site performance? To find out, we measure advertising’s performance impact on a few popular sites.

Are slow FCP scores getting you down? Worried that website performance is frustrating your users and hurting your SEO rankings? This FCP cheat sheet has all the tactics (with links) you’ll need to have screaming-fast FCP scores. First Contentful Paint (FCP) is a measurement of how long it takes to show the user the first bit of content. Measuring FCP encourages your website to respond quickly to requests so that users know their request has been received.

First Contentful Paint, or FCP, measures the time take to render the first element of a webpage. It’s a modern, user-centric measurement of how fast users see a response from your website. Here’s everything you need to know about the metric and how to use it. FCP is one of the Core Web Vital performance metrics that measure user’s perceived performance of websites. These metrics are incredibly important to delivering fast user experiences, and avoiding SEO performance penalties.

Earlier this month, David’s heartfelt posting about leaving Mozilla made the front page of Hacker News. Traffic increased by 800% to his already-busy website, which slowed and eventually failed under the pressure. Request Metrics monitors performance and uptime for David’s blog, and our metrics tell an interesting story. Here’s what happened, why, and what you can do to prepare your site for traffic surges.

Web performance used to be easy. You’d time how long a page takes to load, easy. But the rise of client-side JavaScript has introduced bold new ways for websites to be frustratingly slow. Measuring this new slowness will take new metrics. Google calls them the Core Web Vitals. Each of the Core Web Vitals measures a different aspect of how a web application responds. This post will take a look at each of these metrics, what they measure, and how to use them.

Google Lighthouse helps you identify page performance issues. It generates an overall performance “score” to make you feel good (or bad) about your site’s speed. This score can be useful, but has some limitations. Lighthouse is an automated tool for assessing web page quality. It generates metrics for performance, SEO, accessability and more. Google has been promoting it as THE way to measure website quality.