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Web Performance Calendar

The speed geek's favorite time of year
2023 Edition
Dec 2023
Photo of Sander van Surksum

At the recent PerfNow conference, Tammy Everts highlighted a major challenge in web performance: the excess of different metrics. This issue becomes clear when considering a scenario like a retail company launching a new website. The web development team tracks various metrics like load time, user interaction, and server response times. However, for the marketing […]

Dec 2023
Photo of Stéphane Goetz

Introduction I wish to bring you with me on a journey to learn about optimizing a library for localization, I would like to share my learnings with you on benchmarking, profiling, and optimizing. At Swissquote Bank, we use client-composed micro-frontends, and our platforms are usually available in at least 8 languages. To support this requirement, […]

Dec 2023
Photo of Fershad Irani

Recently, a post from the web performance monitoring tool DebugBear about why they won’t report website carbon emissions in their platform caught my attention. It’s a very good post, pulling together information from a lot of sources, and presenting the reasoning behind their decision. As I read it, I found myself nodding along to parts […]

Dec 2023
Photo of Ethan Gardner

Earlier this year, I was exploring data on the sites I work on and found that a 500ms reduction in the session’s median First Contentful Paint (FCP) results in a 20% increase in user engagement. By definition, conversion events, such as purchases, only occur in engaged sessions. Given my employer’s desire to boost conversions, it […]

Dec 2023
Photo of Ivailo Hristov

99.9. That’s the percentage of origins with a good First Input Delay score on desktop. Source: HTTP Archive Seeing these statistics, it’s easy to conclude that the web peaked in responsiveness. However, we all know that these numbers do not illustrate the real world. You’ve probably experienced a laggy or glitchy website at least once […]

Dec 2023
Photo of Jacob Groß

Revisiting a study of the fastest way to parse large chunks of JSON such as those often used in SPA-type applications to set up state. In 2023 things have changed compared to 2019.

Dec 2023
Photo of Brian Louis Ramirez

An analysis of Speed Kit RUM data on over 780 e-commerce websites shows: INP is worst on product category pages (AKA “product listing pages”). Several common patterns are responsible for sluggish responsiveness on listing pages.