Search Engine Optimization | Internet Marketing | Web Design | Web Copywriting | Link Popularity | SEO Training

Why Standards Compliant Valid Code Matters

A thesis by Dagfinn Parnas, a graduate student at the University of Bergen , highlights that 99% of all websites contain invalid mark-up and fail to comply with W3C standards. The entire thesis is posted online in PDF format.

Parnas used a data set of 2.4 million randomly selected URLs from the Open Directory Project's index to evaluated compliance. He discovered that less than 1% the pages complied with W3C coding standards.

Common Problems

The most common problems may seem trivial:

  1. No Document Type Definition (DTD) declaration
  2. Missing required attribute
  3. Non-standard attribute
  4. Omitted end tag
  5. End tag not open

If a document is missing a closing </p> tag or a Document Type Declaration, modern browsers, especially Internet Explorer, are very adept at interpreting eronious code and will usually oblige by displaying the page the way it was intended to be seen. This has spawned a breed of coders who rely heavily on browser technology to interpret their code and display pages correctly.

So why worry about validation?

While Internet Explorer's quirky mode might render a document that omits a closing TABLE tag, Netscape, which strictly adhere to W3C standards, can display a 'broken' page or completely ignore the table and its contents.

This creates problems for Screen readers like Jaws. Screen readers read aloud the content of web pages and are used by people with vision problems. Since these screen readers are simple text browsers they often encounter problems with HTML code errors and invalid mark-up.

Incorrect search engine indexing

Powerful browsers like Internet Explorer may not care if you omit a closing TABLE tag but a search engine spider does!

Search engine spiders are the most basic text browsers and coding errors may render large amounts of your page content invisible to them, just because human visitors can read your page doesn't mean search engines can.

As you can see coding errors can cause problems with layout, accessibility and search engine spidering which means you could be turning away potential customers from your site who may never to return. That's only if they can find the site in the first place!

Checking your code for validation errors

W3C's online validation tool makes it simple to check your pages for errors and validation problems; it even offers some help on how to rectify the problems it finds.

It's critically important as part of a search engine optimization campaign that coding errors are found and fixed. Just because you can see your WebPages rendered perfectly in your favourite browser doesn't mean that other visitors using different browsers or search engine spiders are seeing the same thing.

Now Take Action

Take the first step towards great search engine positions and generating more sales, request your free search engine optimization quote or to talk us directly on 0141 416 0211 if your business is located in the UK or 69 347 5142 if your business is located in Spain.

Search Engine Optimisation Satisfaction Guarantee
Design Insite,
Search Engine Optimization,
Glasgow, Scotland, UK.
Tel +44 0141 416 0211
Design Insite,
Search Engine Optimization,
Estepona, Spain.
Tel +34 693 475 142

Latest Clients