
As organizations understand the findings of the Cyber Monday Web Performance Index and look to improve their site performance for the next Cyber Monday shopping day, I wanted to offer a few recommendations to help any organization improve in 2017:
Start with 3 Key Findings from the Cyber Monday Web Performance Index
1. Top-Performing Sites Don't Rely on Third-Party Scripts as Much
Relying on third-party hosts for scripts on busy traffic days creates problems for site performance. For example, if your site is pulling a third-party hosted jQuery script share with other sites, the increased traffic from all those other sites can slow down the third-party server and kill page load time.
The number of requested domains matters as well. In the case of the Apple store home page, the browser connects to just 4 domains, all controlled by Apple, whereas The GAP's website pulls content from 74 different domains located all over the world. While some third-party content may be too burdensome to develop internally, content that can be should be.
2. The Servers Are Faster and Closer to the Visitor
Just because you can access the site quickly in San Diego doesn't mean a customer in New York is having the same experience. The physical distance between the visitor and server matters. The test found, for example, that Avon's website takes about 1.8 seconds just to initially respond, while HomeDepot.com takes 300ms. The best-performing sites leverage Content Delivery Networks to bring the content to servers closer to their audience, dramatically improving load times.
3. Faster Sites Structure Web Pages So Content Loads Before Scripts Run
Scripts can interfere with the web browser's rendering process and significantly increase load times. For instance, when a browser encounters an image, it can start the download process and move on to the rest of the page; however, the browser has to stop and wait for a script to load before continuing. It's a best practice, then, to put scripts at the end of the page so the DOM can finish (or come close) before needing to pause.