Developers spend lot of time optimizing performance of web servers. There are many good reasons for doing this, such as fewer servers in a data center and lower probability of overloading those servers. However, the benefits of web server optimization are often negligible for the user experience. Surprisingly, it might take as little as 10% of the total page load time to download the HTML document that is generated on the fly by the web servers.
The typical issues impacting the performance are:
- The browser needs to download too many images.
First step in optimization is to minimize the number of HTTP requests. These simple tips can easily reduce the load time by 50%:
- Merge all CSS files into a single file.
- Use spriting to merge multiple images referenced by CSS into one image.
Users expect to see something on the screen as quickly as possible. If they need to wait too long, they are likely go to another web site (temporarily or never comes back). The content shown first should be the content that users are most interested in. Other content, such as ads can be loaded later.