Section 14.8. Download Statistics | Dreamweaver 8[c] The Missing Manual

14.8. Download Statistics

Remember the joke that WWW really stands for "World Wide Wait"? Even as more and more people upgrade to speedy DSL and cable modems, file size is the constant foe of the Web designer. What takes only a moment to load from your computer's hard drive could take minutes to travel across the Internet. The more information you put into a Web page, the more time it takes to load.

You can judge how big your page is, and therefore how long it will take to download, by looking at the download stats in the status bar at the bottom of the document window. You'll see something like this: 5k/2 sec . This term indicates the file size of the Web page and how long it will take a visitor to download the page using a 56 Kbps modem.

Unfortunately, the behavior of this once helpful feature has changed. In previous versions of Dreamweaver, the file size and download time took into account linked files like images, external CSS style sheets, and Flash movies. This information provided a realistic picture of download speed, since not only does a page have to download, but any files that page uses (like a photo) also need to travel across the Internet to a visitor's browser. Dreamweaver 8 now shows only the actual size of the HTML file, which frequently is much smaller than bandwidth-hogging graphics or Flash movies. In other words, the statistic's pretty much useless, so don't bother paying attention to it (though file this bit of information away for your next Dreamweaver Trivia Challenge nightyou're sure to win).

Note: People hate to wait. You may think that the graphic design of your Web site is so compelling that even if it takes a full minute to download that zippy new Flash home page, people will stick around.Think again. Research shows that 10 seconds is the maximum amount of time that someone stays focused on a task while waiting. That means if you're designing a Web site for people with 56 Kbps modems, keep your pages below about 45 KB.

GEM IN THE ROUGH
Caching In

Behind the scenes, Web browsers store the graphics they download onto the computer's hard drive. This is a speed trick. If you click your Back button to return to a Web page whose graphics files the browser has already downloaded, the browser simply pulls them out of the cacheoff the hard drive, in other wordsinstead of re-downloading them. This arrangement makes the page load more quickly, since the hard drive is generally much faster than the modem.

As a Web designer, you can capitalize on this standard Web browser feature by reusing the same graphics files on more than one page of your site. For instance, you can create a navigation bar composed of small graphic buttons (Home, Contact Us, Products, and so on). If you reuse those buttons on other pages of the site, those pages appear to download more quickly.

This same trick works for external CSS style sheets. A browser needs to download a complete style sheet with hundreds of formatting commands only once for any page on a site to reuse it. By putting all of your formatting into one or more external files, you can keep your Web pages mean and lean.