The W3C consortium defines valid HTML. They judge whether or not an HTML command or a piece of HTML code is legit–and search engines like legitimate code. However, browsers such as Netscape and Internet Explorer often understand and display HTML code that doesn’t validate. Because your website looks fine in your browser, you assume the HTML code is correct, but that is almost always not the case.
Popular website building programs such as Dreamweaver will often insert non-valid HTML. Even though browsers will often display this HTML correctly, it is not W3C-approved and, therefore, not search-engine friendly.
Validating HTML can be a pain. In fact, it can make you want to tear out your hair and beat on the keyboard with a hammer–but it does pay off in terms of page speed and help with search engine optimization efforts. To make the perfectly optimized site, it should be valid HTML code.
To check if an individual web page validates, type the website address in the box below. Don’t worry if your page doesn’t validate right away. 99.9% of web pages out there will not validate the first time!
W3C HTML Validator Tool
Use the following tool to validate the HTML of your web pages.
HTML References & Resources
- HTML & CSS Guide
- HyperText Markup Language Home Page
- Historical and Early Ideas for HTML
- HTML 4.01 Specification
- HTML 4.0 Specification
- HTML 3.2 Specification
- HTML 2.0
- Web Content Accessibility Guidelines 1.0
HTML Validation Tools & HTML Editors
- Authoring Tool Accessibility Guidelines 1.0
- HTML Kit (Full Featured HTML Editor)
- Web Page Backward Compatibility Viewer
- Page Valet
- W3C Tidy your HTML
- HTML Tidy Project
- JTidy (Java Version of Tidy)
- Excel to Web Table Converter
- HTML Editor for the Mac