Adding HTML5 Validation to Visual Studio

For HTML5 validation, you need to install IntelliSense and validation support to Visual Studio. HTML5 is supported by Visual Studio 2012.

VS 2010 had IntelliSense support, but VS 2012 added corresponding snippets making it fast and easy to write markup.

Follow the steps: 

• Launch Visual Studio 2012 
• Go to Tools > Options menu 
• When Options configuration screen is displayed, go to Text Editor > HTML > Validation.