The Week in Website Performance News

This Week in Website Performance is a weekly feature of the blog. It summarizes recent articles about website performance. How to make your web site better, how to improve your users experience when they come to your website and how to optimize the overall experience. Why? Because your friends at care.


Firefox 29 Brings Improvements in asm.js Performance, New Web API

Author: James Chesters

After almost a decade of service, Firefox has just released a new line of updates in version 29, including improvements in asm.js performance. Asm.js is a subset of JavaScript developed by Mozilla and allows performance-intensive applications, including games, to run at near-native speed without plugins. Additional improvements to Firefox 29 are new web APIs, including Web Audio API and CSS Flexbox, and a finalized and enabled Gamepad AP. One new feature of Firefox 29 is Firefox Sync, which provides users access to Firefox’s “Awesome Bar” browsing history, saved passwords, bookmarks, open tabs and form data.


Why Ecommerce Sites That Use a CDN Take Longer to Become Interactive (and Why You Still Need a CDN)

Author: Tammy Everts

Recent findings in a study of the top 500 ecommerce sites show that the median CDN-using page took an entire second longer to become interactive than the median non-CDN-using page. The culprit though is how the pages are constructed, which has nothing to do with a CDN or not being present. The top four performance issues that retail sites must address in this regard are server-side processing, latency, unoptimized images, and third-party scripts.


Apple has its own JavaScript accelerator in the works

Author: Serdar Yegulalp

Apple has recently applied an upgrade to its own JavaScript engine called JavaScriptCore (aka “Nitro”) for WebKit. Codenamed “FTLJIT,” these latest changes will give Apple’s JavaScript a significance boost in performance. The upgrade uses the LLVM compiler as the JIT (just-in-time) compilation system. Testing and cross-platform comparison suggests that FTLJIT could soon rival even Google’s Chrome V8 and Firefox’s SpiderMonkey, based on how well it runs JavaScript code that is not specifically optimized for asm.js (Mozilla’s version of JS developed to run at speeds near native code).