It is quite true that AJAX doesn’t work in all web browsers. Reading from its name, AJAX requires JavaScript. This alone means that AJAX applications will not be able to function properly in web browsers and devices that do not support JavaScript. For this reason it may not be accessible to many typical Web users.

The only possible solution to these problems is to either provide a non-AJAX alternative to your application or to allow your AJAX application to continue to function if JavaScript and XMLHttpRequest are not supported. But it will be much hard to achieve such an arrangement. While developers may choose to require the users to use a browser that supports AJAX, they must understand that such requirements may not be possible for all users – especially those using portable devices or older web browsers.