Last updated: October 25, 2017
Check the HTML markup validity of your web documents by verifying whether your web pages follow the rules of the markup language that you used to build them. To do so, use the free W3C Markup Validation Service. Each markup language, such as HTML, XHTML, SMIL, and others, has its own set of technical specifications. If the pages of your site do not conform to the technical specifications for the markup language you use, the web browsers may not display them properly.
The free Markup Validation Service allows you to validate your web pages by URL, by File Upload or by Direct Input, so you can be confident that visitors to your site see your web pages in the manner you intended. To validate a document by URL, input the web address into the Address input field. Alternatively, browse for a file from your computer, and upload it for validation, or type the code into the Direct Input field. If needed, click the More Options link to set character encoding and document type, and other key validation options.
To use the free W3C Markup Validation Service, please visit: http://validator.w3.org
Thank you for visiting Tech Help Knowledgebase to learn how to check the HTML markup validity of web documents.
Image credit: Pixabay / MianShahzadRaza