A web site that is being launched should be optimized for all browsers. A visitor to your site won’t change their computer system (screen resolution, browser version,…) in order to see your site. Your visitor is likely to turn away quickly and go to another source for information because there are so many sites on the Internet.
Here are a few statistics  recently taken from a popular web site (http://www.lovetest.com ) which shows what kind of environment is supported. We analyzed 200,000 visits during the first 14 days of December 2005 and then again 450,000 visits in August 2007. The site is mostly visited by teenage girls and women. LoveTest.com is part of the entertainment web sites run by Euregio.Net .
In my opinion, you should design your web site for at least 800×600 pixel as this allows most people to see your site correctly. If you know that you have mostly technical people visiting your site, then you could design it for 1024×768 pixel as these visitors tend to have larger screens and newer computers.
|1600×1200||0.18%||–||0.12%||If you design for 800×600 you can support at least 96.93% of your visitors. In 2002, “only” 87,02% of your visitors supported 800×600 or greater. You can even design for 1024×768 and support 84.11% of all visitors.|
|800×553||–||–||0.14%||If you design for 800×600 or more then you might lose around 1% of your visitors. Most unreported visitors will use higher resolutions.|
The color depth is not as important as the screen size, but you should also take it into account where possible.
|32 bit||87.56%||77.10%||26.03%||If you design for 16-bit you can support 99.73% of your visitors.|
|16 million (24 bit)||3.37%||4.97%||11.23%|
|65536 (16 bit)||8.80%||17.21%||51.98%|
|15 bit||0.00%||–||0%||0.27% of your visitors support less than 16-bit.|
|256 (8 bit)||0.21%||0.60%||5.81%|
On the LoveTest.com site, we noticed that in December 2005, most people used Internet Explorer 6 on Windows XP and it’s still the case in August 2007. Firefox is gaining ground on all platforms and accounted for around 15% of our visits. Windows XP is the most popular operating system while Vista is now at around 7% of all Windows users. Macintosh is getting market share as well.
When you build a web site, you should make sure that it works correctly with Internet Explorer 6.0 (on Windows) as it’s used by 63% of the visitors. Internet Explorer 5.5 or below is used very little. Internet Explorer is used by 36%. To make your site compatible with other operating systems, you should test it with Firefox and Safari. That way, you’ve got the majority of people covered. If you’ve got more time on your hands, also test the site with Opera, Mozilla and Netscape.
Microsoft will discontinue support for Internet Explorer on the Mac by the end of the year 2006 (News.com has the whole story… ). That said, you shouldn’t worry too much as only a very small fraction of people still use IE on the Mac. Safari and Firefox are the most popular browsers on MacOS X. Beware that there are some important differences between Safari 1.x and 2.x. You should check your site with both versions.
Browser Photo  is a service run by Keynote Netmechanic who will take screen shots of your web site using various browsers and platforms. If you’d like, you can also test most browsers on your own computer. You just need to install several browser versions on your computer and test all pages of your site.
Here is the majority of browsers you should test. If you work on a Macintosh computer, you can install all those browsers on the same machine using various operating systems through Microsoft Virtual PC . VirtualPC also works with Windows based PC’s  and lets you use various Windows versions simultaneously (Windows 95, 98, ME, 2000, XP, NT, XP,…)
MacOS / MacOS X
Netscape Navigator 2.0 (Mac)
Netscape Navigator 4.0 (Mac)
Netscape Communicator 4.5 (Mac)
- Netscape Communicator 4.7 (Mac) 
- Netscape Navigator 6.0 (Mac) 
- Netscape Navigator 6.2 (MacOS X) 
- Netscape Navigator 7.0 (MacOS X) 
- Netscape Navigator 7.2 (MacOS X) 
- Netscape Navigator 8.0 (MacOS X) 
- Netscape Navigator 9.0 (MacOS X) 
Internet Explorer 4.5 (Mac)
Internet Explorer 5.0 (Mac)
- Internet Explorer 5.1 (Mac) 
- Internet Explorer 5.2 (MacOS X) 
OmniWeb 4.0 (MacOS X)
WebTV Viewer 2.0 (Mac-Emulator for WebTV 1.2)
WannaBe 1.0 (Mac — text-only browser)
- Mozilla 1.2 (Mac) 
- Mozilla 1.7 (MacOS X) 
- Safari 1.2 (MacOS X) 
- Safari 2.0 (MacOS X) 
- Safari 3.0 Beta (MacOS X) 
- Firefox 1.0.x (MacOS X) 
- Firefox 1.5 (MacOS X) 
- Firefox 2.0 (MacOS X) 
Internet Explorer 4.0 (Windows)
Internet Explorer 5.0 (Windows)
Internet Explorer 5.5 (Windows)
- Internet Explorer 6.0 (Windows) 
- Internet Explorer 7.0) Windows 
- Netscape Navigator 4.8 (Windows) 
- Netscape Navigator 6.0 (Windows) 
- Netscape Navigator 7.0 (Windows) 
- Netscape Navigator 7.2 (Windows) 
- Netscape Navigator 8.0 (Windows) 
- Netscape Navigator 8.0 (Windows) 
- Netscape Navigator 9.0 (Windows) 
WebTV Viewer 2.6 (Windows-Emulator for MSNTV 2.0)
- Mozilla 1.1 (Windows) 
- Mozilla 1.7 (Windows) 
- Firefox 2.0 (Windows) 
- Blazer 2.0 (Palm PDA)
- Telnet (to load the raw HTML and headers from a web site. If you know the HTTP protocol you can manually enter a user agent/browser name)
- Opera  (Mac/Windows/Linux)
Quick Check List:
Here’s the quick checklist to make sure your site works for most people worldwide.
- Design your site for 800×600 pixel
- Graphics should be 16-bit color
- Test your site on Windows with Internet Explorer 6.0 and 7.0
- Test your site on MacOS X with Safari 2.0 and Safari 3.0 beta
- Test your site with Firefox 2.0
If you expect your site visitors only coming from North America or Europe and industrialized countries, then you can use these guidelines:
- Design your site for 1024×768 pixel with 24-bit color
- Test your site on Windows with Internet Explorer 6.0 and 7.0, Safari 3.0 beta on Mac and Firefox 2.0 on any platform
Keeping this checklist in mind, you should be able to accommodate around 98% of all your visitors.
Good luck with your web publishing projects !