The tests are simple and easy to conduct and use the W3C's own tools.

Web Page Construction

Web pages are constructed using hypertext mark-up language (HTML) and cascading style sheets (CSS). HTML describes the content of a web page, while CSS stipulates how it should be displayed. (Not all web pages use CSS, but most now do.)

The two W3C tests check whether the HTML and the CSS components comply with the internationally recognised standards.

Web pages are viewed using web browsers, such as Microsoft Internet Explorer and Mozilla Firefox. Just because a web page can be displayed in one of these web browsers does not mean that it is compliant. In fact, most web browsers are very good at guessing what the designer intended, even if they haven't abided by the rules!

The problem is that by deviating from these rules, the designer introduces a degree of subjectivity into the equation about how the page should actually be rendered. It would be much better if the design complied with the standards, so barring bugs in the browsers themselves, the page should look the same regardless of the browser being used.

Problems with Non-Compliance

It might be argued that it is rather academic whether a web page complies with the acknowledged standards if it displays as expected in the popular web browsers. However, you should think again before accepting this position.

Firstly, just because a non-compliant page renders in some browsers does not mean it will render in all browsers. This clearly means you run the risk that the web pages you have paid for will not render correctly for some people, excluding some of your potential audience, and perhaps damaging your brand at the same time.

Furthermore, many jurisdictions have implemented laws to make the web accessible to people with disabilities, such as the Disability Discrimination Act 1995 in the United Kingdom. Failure to comply with these laws can have serious consequences.

The problem is that many of the specialist browsers that allow people with disabilities to access web pages rely on them being compliant. You could well run foul of these disability discrimination laws if your web pages are not accessible to people with disabilities because they do not comply with the standards. At least, if your pages are compliant, you are one step closer to ensuring they are accessible.

Another good reason for ensuring that your web pages are compliant is to ensure you get better search engine placement. People are not the only things to access your web pages. Web search engines also access them in order to index them.

Clearly, it helps these engines immensely if they can understand the pages, which can only reliably happen if they comply with the relevant standards. Consequently, if your pages do not comply properly, they may not be so favourably placed on the likes of Google and the other search engines.

In essence, by accepting non-compliant pages from your web designer, you reduce your target audience. You reduce your audience because your content is less likely to be indexed properly and you reduce your audience by potentially excluding some of them because they can't access your pages properly.

Worse still, in some jurisdictions, you may have to face the consequences of having unfairly discriminated against people with disabilities.

How Can I Test My Pages?

Hopefully, this article has persuaded you that you've got nothing to lose by insisting that your web pages are designed to be compliant with the standards.

It does seem sensible to select a web designer who appreciates the importance of these standards and who demonstrates their commitment to them by ensuring their own site complies.

The W3C provide two easy to use tools to test compliance with the various standards for HTML and CSS, which you can readily use to assess your designer's technical skill and to ensure that your site complies with the standards when it is delivered.

All you need to do is visit the tools' respective web pages (given below) and type in the address of a web page you want to test (or better still just copy and paste it from the browser's address bar). Simply then just click the ?Check? button to run the tests. If the results come back green then the page complies. If it comes back red then there are compliance issues. The report will detail the errors.

Obviously, one or two errors per page may be down to careless slips, but large numbers of errors will clearly indicate that the designer isn't sticking to the standards.

I'll leave you to conclude what to make of those web designers who advertise that their sites comply when they manifestly don't and what to do if you find your site doesn't comply when you've been told it does?

W3C Markup Validation Service

W3C CSS Validation Service