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Yottaa Expert Eval – Web Performance


Each Friday Yottaa CTO Bob Buffone digs into the data and evaluates the web performance of a new website.  Recommend a site for next week’s Expert Eval in the comments below or @Yottaa on Twitter! #ExpertEval 

This week I examined  It’s an E-commerce site dedicated to bikes and equipment for urban commuters. The site is built on the Magento e-commerce platform, so in many ways, it’s a fairly typical website.
Commuter Bike Store

eCommerce sites require fast page loads in order to make money.  On most eCommerce sites, a visitor must make it through about 10 webpages before the checkout is finished, and provide lots of information along the way. Any delays in page load time or usability will cause visitors to abandon their shopping cart, the checkout process, and the website altogether.


I did a real-time assessment of the homepage, and you can see the results on the
Commuter Bike Store assessment page. A couple of stats stood out:

  • 6.1 seconds – the time it takes to load the home page. This is about 2x higher than it should be. Ask anyone who has researched Internet user behavior, and they’ll tell you that a website should load in about 3 seconds in order to retain its visitors.  E-commerce sites are especially susceptible to this rule since most of their clicks will have probably come from Google. I did a search for “commuter bikes” and 9,400,000 results were returned. You do not need to see bounce rate stats to know that if a site loads slowly, a user can hit the back button and go to one of the many other results in the blink of an eye.
  • 1.45 seconds – the time for the browser to download the homepage. This, too, is higher than it should be. If the goal is to have a website fully displayed in under 3 seconds, you cannot have that much time devoted to downloading the HTML file.
  • 88 – the number of assets required to display this page. For an e-commerce site, this is actually a pretty good (meaning: low) number.  But if you dig into the data, you’ll see 12 CSS assets and 17 Javascript assets included in the 88 number. As individual asset types, these numbers are simply too high to be optimized easily.  Also, the 51 images on the page is a lot, but it’s typical of an e-commerce site.  People want to see what they’re going to buy, so having lots of images is unfortunately unavoidable on most e-commerce sites.

Asset Breakdown

Next, I ran the website through the Yottaa Site Speed Optimizer Preview to see what the performance improvement would be by applying CSS and JSS concatenation and using DataURIs to encode the images.

Below is the breakdown of the assets after the default optimizations were applied. You can see that concatenation reduces the asset count by 37%, removing 32 assets required for the rendering of the homepage.

This reduction in assets resulted in the page load time dropping by 25%, to 4.69. This is with only the basic optimization turned on. Also, applying a Safe HTML caching feature took the 1.45-second download time of the HTML file down to 500 milliseconds, saving almost another full second from the homepage load time.

There are a number of great resources on the web for learning how to apply these optimization techniques yourself.  One important resource is Yahoo’s YSlow principles.  Another good place to start is this article by our CEO, Coach Wei, entitled ”
Seven Mistakes that Make Your Website Slower.”

Want to take the easy route instead?  Signing up for the Yottaa Site Speed Optimizer‘s 14-day free trial will take only 5 minutes, and will get you all the techniques we mentioned and more.

Don’t forget to recommend a site for next week in the comments or on Twitter – #ExpertEval

Bob (Buffone)


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