Are you validating your website's HTML/XHTML and CSS? If not, you should be.
Having HTML/XHTML and CSS code that is compliant with standards is important for the following reasons:
- It increases the likelihood that visitors using different browsers are still seeing your website as you intended it to be seen.
- It increases the likelihood that visitors accessing your website using devices other than a PC will be able to access it successfully. Don't forget that a significant number of people access the internet through portable devices, for instance!
- It helps those with disabilities access your website. For a larger business in the United States, compliance with ADA standards may be an internal requirement.
- It can assist with SEO.
- I have personally found during the process of developing a website that validation usually results in cleaner code that is less bloated, which can help boost load times.
Here are some easy-to-use online tools for doing just that:
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W3C Markup Validation Service
The standard for checking the validity of HTML/XHTML pages. -
W3C CSS Validation Service
The standard for checking the validity of cascading style sheets. -
Cynthia Says
Check to see if your website is compliant with Section 508 standards and WCAG guidelines. -
WAVE
WAVE is a nifty tool that provides a visual analysis of a web page's accessibility. I love this! -
WDG HTML Validator
This HTML validator supports the validation of multiple URLs and entire websites. -
Web Page Purifier
This tool allows you to take a web page and restricts its HTML to the selected standard. Also be sure to check out the Web Page Backward Compatibility Viewer.



4:34AM on 16th March 2011
Hi! Great list but do you know of any service (paid) that will automatically validates all pages within your site and send you alerts once it encounter errors or something needs to be fixed? I would like to eliminate my time on checking individual pages.