By Melissa J Luther
If you’ve been around the Internet for any length of time, you know about the importance of keywords, backlinks and meta tags to search engine optimization efforts. Content and code are not the only things that matter, though. Site speed is also important.
Fast page loading has long been important to providing a good user experience. SEO experts have also suspected that search engines, in their efforts to serve up results that are both relevant and user-friendly, would also come to care about speed. Google made it official in April, announcing that site speed is now a part of their search ranking algorithm.
Some aspects of your site load speed are beyond your control. You can’t change the Web protocols that browsers and servers use to communicate, for example, although efforts are underway to develop faster methods. An interesting project is Google’s SPDY (pronounced “speedy”) protocol that may allow for up to 55% quicker page loading. In the meantime, there are other ways to improve communication speeds.
First, you need to know how long your site takes to load. There are several tools for measuring this, but two good ones are YSlow, a Firefox extension and PageSpeed, a Google add-on for Firefox. Both analyze your pages and suggest improvements. Here are some simple fixes.
Limit DNS Lookups
When you enter a URL into your browser, it needs to find out where that page is located. It does this by contacting a DNS resolver, which sends back the server’s IP address. The browser cannot download anything until it has this address. If your page includes elements from multiple locations, then the browser must make multiple DNS lookups. Try not to require more than four DNS lookups on a page.
Limit HTTP Requests
Every element on a page generates an HTTP request in order to load in your visitor’s browser. The more requests generated, the more back-and-forth required between the server and browser, and the slower the page loads.
Reduce HTTP requests by:
- Caching as much as possible. Items cached by a visitor’s browser don’t have to be downloaded with every page request. A good place to start is by consolidating scripts and CSS. Create one external script file and one external CSS file. Each file will be downloaded once and cached, making subsequent pages load faster.
- Using CSS sprites to consolidate multiple background images. One image generates only one HTTP request. Use CSS properties to display the appropriate image segment, as needed.
Increase Parallel Downloads
Downloading multiple page elements simultaneously is called parallel download. This speeds page load, but browsers can handle only a limited number of parallel downloads from any one domain. However, they can perform additional downloads from other domains/subdomains. So, by creating a few subdomains and storing images and other documents for download there, you increase your parallel downloads. Just don’t use too many or you’ll create excessive DNS lookups.
There are plenty of other ways to optimize your site, but these are easy to implement and offer quick results.
About the Author
Melissa J Luther, owner and founder of LookSee Information Solutions, LLC, helps small businesses create and maintain a strong Internet presence. She takes a multi-channel approach, with a well-optimized Web site as the center of an Internet presence that includes content creation, PPC advertising, linking and social media as appropriate.