Web Performance

Une présentation des fonctionnalités avancées de WebPageTest (scripts, API, etc.)

"Tim Kaldec et Yoav Weiss se sont donc inspirés de ce mécanisme [Content Security Policy], pour le transposer au sujet de la performance web, en proposant un nouvel en-tête HTTP (Content Performance Policy) permettant de déclarer précisément le degré de compatibilité d'une page avec certaines bonnes pratiques de performance web. À la charge ensuite du navigateur web, de forcer l'application des bonnes pratiques annoncées qui ne seraient pas respectées par l'éditeur."

"This method builds on the Flash of Faux Text (FOFT) using a two stages loading process (sounds like, but is not actually rocket science), but instead of a full Roman web font in the first stage, it loads a small subset of the Roman web font"

"I want to share with you my simple two-step secret to improving the performance of any website. 1. Make sure that the most important elements of the page download and render first. 2. Stop there."

"Les 3 caches ? C'est comme les 3 coquillages : on peut faire sans, mais les gens du futur se moqueront."

"Les 3 caches ? C'est comme les 3 coquillages : on peut faire sans, mais les gens du futur se moqueront."

"If you want to improve performance, you must start by measuring performance. But what should you measure?"

"Submit a URL to generate a node map of all of the requests on the page. Rapidly identify what third-parties are on your site, where your transmitted bytes are coming from and how slow your domains are !"

"... Quelle que soit l'issue, le budget de performance en tant qu'outil aura fait son office : vous vous serez interrogé sur les impacts de cette évolution, et vous en aurez maîtrisé les conséquences."

we can tell the browser which sockets we will need ahead of initiating the actual requests via the new preconnect hint shipping in Firefox 39 and Chrome 46

content adaption without increased client latency

Etude de cas Performance Web sur le site de  Wired

"Asm.js is a clear step towards enabling near-native performance for the Web platform, which is why we're excited to bring it to Chakra in an upcoming release."

Use this file to prevent your computer from connecting to selected internet hosts. This is an easy and effective way to protect you from many types of spyware, reduces bandwidth use, blocks certain pop-up traps, prevents user tracking by way of "web bugs" embedded in spam provides partial protection to IE from certain web-based exploits and blocks most advertising you would otherwise be subjected to on the  internet.

Video there: https://www.youtube.com/watch?v=FEs2jgZBaQA

"Calculate visual performance metrics from a video (Speed Index, Visual Complete, Incremental progress, etc). This is a command-line port of the WebPagetest mobile video processing and metrics code."