readme.markdown CSS Stress Test This project is a bookmarklet for stress testing the CSS on any given webpage. andyedinborough/stress-css andyedinborough/stress-css
Why you should care about CSS page performance Why you should care about CSS page performance Development: The estimated time to read this article is 5 minutes If there’s one thing I’ve learned over the years as both a user and creator of websites, it’s that performance matters. Whether it is how fast the page loads or how it behaves once it’s in place, how well that page works has a direct impact on my and other user’s opinions of that website. A website that performs quickly and smoothly feels high-quality and that feeling translates to the brand it represents.
Pagespeed | Google

Making a Fast Website Making a Fast Website It’s always been important to make your website fast. Not only is it obvious visitors are going to prefer it but it’s now well-known that Google uses loading speed as a ranking metric. The initial page load of your website is perhaps the most important. The longer it takes to load the more visitors are going to press back and find an alternative. A slow website is something that could potentially frustrate visitors so it’s important to try and remove it from the equation. Jakob Nielsen is an authority on usability and has studied response times extensively.
What do defer and async mean? By default, a <script src=...></script> tag is evil! javascript - Defer Attribute (Chrome) javascript - Defer Attribute (Chrome)
The Exceptional Performance team has identified a number of best practices for making web pages fast. The list includes 35 best practices divided into 7 categories. Minimize HTTP Requests tag: content Best Practices for Speeding Up Your Web Site Best Practices for Speeding Up Your Web Site
JavaScript Performance JavaScript Performance Last night I spoke at the San Francisco JavaScript Meetup . I gave a brand new talk called JavaScript Performance that focuses on script loading and async snippets. The snippet example I chose was the Google Analytics async snippet . The script-loading part of that snippet is only six lines, but a lot of thought and testing went into it. It’s a great prototype to use if you’re creating your own async snippet.
A big part of accelerating websites is eliminating bottlenecks. Scripts are likely the most discussed bottlenecks, but CSS files are equally bad. CSS files will block all subsequent downloads if there’s a script (internal or external) in between – which is the case on practically any real page. Eliminating the CSS bottleneck | Eliminating the CSS bottleneck |
The async support as specified by google is achieved using two parts: using script on your page (the script is supplied by google) to write out a <script> tag to the DOM.that script has async="true" attribute to signal to compatible browsers that it can continue rendering the page. The first part works on browsers without support for <script async.. tags, allowing them to load async with a "hack" (although a pretty solid one), and also allows rendering the page without waiting for ga.js to be retrieved. The second part only affects compatible browsers that understand the async html attribute FF 3.6+ FF for Android All VersionsIE 10+ (starting with preview 2)Chrome 8+ Chrome For Android All versionsSafari 5.0+iOS Safari 5.0+Android Browser 3.0+ (honeycomb on up)Opera 15.0+Opera Mobile 16.0+Opera Mini None (as of 7.0) The "html5 proper" way to specify async is with a <script async src=" javascript - Which browsers support <script async="async" /> javascript - Which browsers support <script async="async" />
Testing/Speed Test/Etc | Webdev