As a friend of mine on Twitter amusingly put it "Welcome to the 1990's :)". The thing which interested us most was whether their late arrival to cyberspace meant that they had learned lessons from longer established online retailers that site performance is critical to their success.

Web site	Page Fully loaded (Seconds)	HTTP Requests	Google Page Speed Score	Size KB	WebPageTest.org results page
www.zara.com	3.7	19	90/100	369	Results
bananarepublic.gap.eu	9.0	49	67/100	855	Results
www.hm.com	12.7	53	67/100	1,252	Results
www.gap.eu	12.5	49	66/100	610	Results

All tests were run using webpagetest.org using their UK test location in Gloucester with IE7 browser and a 1.5MBps internet connection. Full results can be viewed by clicking the Results link. We took the fully loaded time as the measure for comparison. 

We found that the Zara site outperforms the others by some margin.  As you can see from the results the reason that the load time is faster is because of 2 very important factors. 

1. Firstly the number of Requests required to load the home page is only 19 compared to far more for the other sites. If you have a rich web site with lots of images, JavaScript, CSS etc then that means more round-trips from browser to server. Each round-trip takes time which could be <50ms if you are close to the server but could be +300ms if you are in another country or on a connection with high latency. The number of round-trips is the most important consideration when tuning your page load times. Techniques like merging of JavaScipt and CSS, image spriting (combining several images into one) and CSS inlining of images (embedding background images as base64 within the CSS file) will all help to reduce the number of round-trips required to load the page.
   
   
2. Secondly the size of the page is smaller with 369K of data to download compared much larger amounts for the other sites. Overall 'weight' of page is the second most important things when tuning your page load times. Techniques for text based resources like CSS and JavaScript such as minification followed by gzip or deflate compression will help. For images you can try resizing or re-sampling them so that their file sizes are smaller without any noticeable degradation in quality.

All optimization techniques discussed in this article and more can be applied automatically by Aptimize without any code changes. Please contact us for more information about how Aptimize could help your site.

Run a speed test now and find out how you site performs.
http://www.applicationperformance.com/web-site-speed-test