You may not bother with html validation or writing simple and clean code when designing your web site. Later you may find your site is slow loading, appears incorrectly in main browsers and does not rank well for major search engines.
Now there are sites that still do rank well even though html code has many errors. This is because most of current major browsers are still very forgiving of html mistakes, however future browsers will become more html compliant as Internet advances. Sites that have not bothered with html code validation will then fall by wayside or take time and money to be corrected.
That's why you should take necessary steps NOW to make sure that code on your web site is validated.
What is HTML validation?
This is process that analyzes an HTML document in comparison to standard HTML rules, identifying errors and non-standard codes. Web pages are rendered using HTML (Hyper Text Markup Language). As with any language there are rules and standards that should be followed. For example HTML 4.01 Specification (rules and standards) are available at http://www.w3.org/TR/html4/. You can check html validation of your web page by entering your url at: http://validator.w3.org/
7 Benefits of HTML validation
1. Web Site Accessibility - validating your html code helps to pinpoint areas of potential blockage that could prevent search engine spiders or visitors from accessing your website. When you run your site through a code validator it may produce many errors that need to be corrected so your pages will render well. ie include text with your "alt" tags for every < img > tag.
Why should you do this?
-Allows your site to be accessible to a larger audience (vision impaired, motor skill impaired, cognitive impaired)
-Allows your site to be accessed by wider range of devices (hand helds, screen readers, text browsers, search engines)
-Is a requirement for Federal and State Government sites
2. Search engine friendly pages - clean and simple code enables search engines to spider your pages more quickly and completely.
Here's an example: