What needs to be done to ensure a Web site works on a PDA and other different hardware devices?

It is not necessary (or always desirable) to purchase and test Web pages against every combination of hardware device, browser version etc.  Instead you should check that your Web pages are compliant with the version of HTML / XML / CSS that you use.

The testing should be carried out using a HTML / XML / CSS validator rather than relying on checking how it looks using a browser.  A variety of validator are available.

In addition to these (and other) Web-based validators, many authoring tools will have their own validators.

There are a number of validators available for WAP phones.  These may be bundled in with WAP / WML authoring tools.

There may be similar tools available for PDAs.  However if the PDA supports HTML, you will be able to use a HTML validator.

Note that there are a number of WAP emulators available.  These can be used to test out WAP sites.  However, as stated above, it cannot be guaranteed that if a site works correctly in an emulator that it will work in the device itself.

Further Information