With a plethora of different web browsers out there, it is essential to make sure that your website can be viewed adequately on as many browsers as possible if you want to have the largest audience. The two most commonly used browsers are without doubt, Microsoft Internet Explorer and Mozilla Firefox. Since all web browsers read websites a little differently, it is likely that you will need to make a few optimizations to your website to get the highest level of compatibility.
While you will never be able to achieve one-hundred percent compatibility with all the web browsers and possible configurations out there, there are a number of things that you can do to help solve the problem. For a start, your website coding must be done in such a way that it rigidly conforms to W3C standards. Unfortunately, creating your website so that it is as cross-platform compatible as possible often means that you have to sacrifice some special effects available only in specific browsers, although you can have separate versions of the website for each of the most common browsers if you really must.
Using an HTML validator is a good start to making sure that all your code is correct. There is a free service at www.validator.w3.org which can help this process. The programme checks the document type specified on the site and tells the browser what version or HTML the site is utilizing.
With regards to the programmes you use for web design, the best one for creating cross-browser compatible websites is Dreamweaver but it does not allow you to use layers which instead need to be converted to tables. One the flip side, Microsoft FrontPage is perhaps the worst choice since it is heavily biased towards Microsoft Internet Explorer.
Some things that are specific only to Internet Explorer are bgsound tags, page transitions and FrontPage style sheets. Hovering buttons also need to be avoided since they only work in the latest versions of Internet Explorer.
CSS technology can also yield some compatibility issues and although they do not tend to cause a browser to crash, they can severely truncate the way the website is viewed. Creating CSS style sheets needs to be done with a lot of care since in some browsers they may overlap each other creating an illegible mess.
There are a number of other website building programmes that you can try using, but Dreamweaver is amongst the most popular and widely respected for a number of reasons including its bonuses towards compatibility.
Flash has potentially great advantages so long as it is not overused, which, unfortunately, it often is. Also remember that very few mobile devices support flash, so if you are going to have a site which uses Flash frequently, it may be a good idea to have a non-flash version of your site available too. Others do not like to install the extra plug-in that is required by Flash and also, search engines do not track the links in Flash material.
Graphical links are something else that you want to think about since, while these may look great on a proper computer, their use can be severely marginalised on handheld devices. The alt tag should always be used with graphics.
The most effective, and obvious way to make sure that your website is cross-browser compatible, is by testing it out in as many browsers as you can, which will help you to focus on the specific issues and correct them accordingly.
Finally, if you want your website to be viewable on a handheld device such as a Smartphone, then it is often much better for optimization to have a separate version altogether of that site. This is mainly due to the far smaller screens and lower resolutions of such devices whereas most websites are designed to be viewed at a resolution of 1024×768 or higher.