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YouTube

Figure 17-25. http://www.youtube.com

YouTube’s home page (http://www.youtube.com) isn’t very heavy, but it has a low YSlow grade and ends up in the bottom half of response times. Figure 17-26 shows that there isn’t very much parallelization at the beginning and end. Increasing the level of parallelization in these areas would make the greatest improvement to response times.

YouTube HTTP requests
Figure 17-26. YouTube HTTP requests

In the beginning of the page load, the main hurdle to parallelization is the six scripts downloaded back-to-back. As explained in Chapter 8, scripts block all other downloads, no matter what their hostnames are. Additionally, the scripts aren’t minified. Combining these six scripts into a single script and minifying them would decrease the download time. Also, if any of these scripts could be downloaded later in the page, the initial part of the page would be downloaded and rendered sooner.


  

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