What is validation?

Web pages are written in computer languages, such as HTML, which allow web designers to structure text, photographs and multimedia content, and specify what appearance, or style, the page should have.

As with every language, they have their own grammar, vocabulary and syntax, and every document written with these computer languages are supposed to follow those rules.

However, just as text in a natural language can include spelling or grammar errors, documents using computer languages can also include errors.

The process of verifying whether a web page follows the rules for the language(s) it uses is called validation, and the tool used for that is a validator.

A web page that successfully passes this process is deemed 'valid'.

Checking validation

W3C provide an online tool for checking whether a web page passes its validation rules and is, therefore, valid. Click the W3C logo, below, to check your own website:

W3C Markup Validation Service

If your web pages are confirmed as 'valid' you can then display one, or more, of the following W3C logos on those pages to show your website visitors that you have taken the time, and care, to create an interoperable web page.

Valid XHTML 1.0 TransitionalValid XHTML 1.0 Transitional
Valid XHTML 1.0

Valid CSS!Valid CSS!
Valid CSS

You may have already noticed a couple of these logos at the foot of this web page!

Validating your website

If you already have a website we can perform the validation check for you and, if required, make corrections to your pages* so that they can be validated successfully.

W3C Validation
Validation Check & Report £5.00
(per page)
Page Corrections
(HTML, CSS, ASP, PHP programming)
(per hour)

* If your page/s contain certain scripts, plug-ins, embedded content and/or web applications it may not be possible to correct any errors detected during validation without directly affecting that content. In instances such as this we would advise you on the best course of action for that page.
W3C Validation