HTML5 declaration is compatible with IE and html5 declaration with ie

HTML5 declaration is compatible with IE and html5 declaration with ie

<! DOCTYPE html> <! -- [If IE]> <meta http-equiv = "X-UA-Compatible" content = "IE = 8"/> <! [Endif] --> <! -- [If IE 7]> <meta http-equiv = "X-UA-Compatible" content = "IE = 7"/> <! [Endif] --> <! -- [If IE 6]> <meta http-equiv = "X-UA-Compatible" content = "IE = 6"/> <! [Endif] -->

<! DOCTYPE html> is an HTML5 declaration. Only IE8 or earlier versions of mainstream browser browsers are not supported, So IE enters the Quirks mode. However, the subsequent statement can forcibly specify the IE rendering mode, so <! DOCTYPE html> the declaration has no effect on IE.

HTML5 is not as strict as XHTML. For general xhtml pages, it is basically impossible to completely pass the W3C verification standard, but it can be passed after being declared as HTML5.