Web pages can look and behave very differently depending on the browser, operating system, system fonts, screen resolutions, and internet connections. The appearance of colors can vary based on screen resolution, color depth of users' monitors, and video card drivers. The only sure way to get an accurate picture of how your site will look to users is to view it in the varied situations that they will view it.

Be sure to test your pages on all targeted browsers platforms, and system settings. The following items in particular behave differently across different browsers and browser versions:

• HTML and HTML extensions (particularly HTML 4.1 extensions)
• JavaScript, Visual Basic Script, ActiveX and Java applets (use comments to hide script language, which sometimes appears in the view of older browsers)
• Table features, such as background colors in cells
• Page layout and default fonts

Generally, a user with a 28.8 modem should have a sense of the page content or be able to navigate off the page within 10 seconds of download. The rest of the page should load within the next 30 seconds. Users may be willing to wait longer for specific content such as, for example, an online course schedule. Users tend to be less tolerant of slow navigation pages.

Test your Web site to ensure that it will be accessible to users with disabilities. To test for accessibility:

• View the page in a Web browser with various display settings customized (e.g., disable images and see if the page is still readable; enlarge the font and ensure that all text scales to a larger size)
• Print images and pages in black and white to see if they are usable to people who are color blind or people who are using a device without a color screen
• Observe vision-impaired users with screen readers accessing content on your site, or blindfold yourself and access your site with a screen reader such as IBM Home Page Reader