Validation Defined

Just as texts in a natural language can include spelling or grammar errors, documents using Markup languages may (for various reasons) not be following these rules. The process of verifying whether a document actually follows the rules for the language(s) it uses is called validation, and the tool used for that is a validator. A document that passes this process with success is called valid. W3.org

What Can Valid Code Do For Me?

1. Reduce Page Load Time

Having valid code means that a web browser does not need to spend time going over errors to correct bad code which makes the page load faster.

2. No Broken Layouts

Not every browser will correct invalid code. Forgetting to close a tag here or there could lead to a broken site layout and a poor user experience!

3. Browser and User Accessibility

Having valid code means that a website has a greater probability of being accessible to screen readers and ensures correct rendering on wider range of browsers.

4. Sign of Professionalism

With few universally recognized certifications having valid code should be a sign of ability and pride.

5. Easier for Search Engine Spiders To Crawl

Search Engine spiders are simplified browsers looking for content on the internet. Too many errors on page will slow them down and may cause them to leave, just as you may stop reading a site or publication full of grammatical and spelling errors.

What are Common Errors?

Not using alt=” ” tags in images

alt tags allow you to place text on a picture and aid visually impaired users who use screen readers to see the description of the image. Try not to keyword stuff them and place and appropriate description.

Not using &amp

Most people forget that using & in any instance of code, even in a url is not valid and &amp should be used in its place.

Adding extra tags or not closing tags

All tags should be closed off by using /> and usually carelessness or lack of revision is the culprit.

Incorrect Nesting

When using nested elements they must be close in order.

Who Validates and Who Doesn’t?

BBC’s Code validates with 0 errors 0 warnings

Wikipedia validates unless there is an article in a foreign language which causes several errors

Facebook: 40 Errors

Google: 40 Errors

Conclusion

Looking around it’s hit or miss as to who validates their code and who doesn’t. Larger companies can afford to have poor designs and get away with it due to their sheer size(think of your cell phone company or cable company). But can you afford to take the same risks? In the world of Search Engine Optimization every little bit helps to get an advantage over your competition for those few precious spots on the first page.

Check to see if your code validates