Why does IE9 opens in Document Mode as IE7 standards?

Question

When I open a webpage in IE9 with DOCTYPE as

It opens Document Mode as IE7 standards.

I need default IE9 stan

Answer 1

The issue appears to be specific to the combination of IE9 and compatibility mode. For us, we cannot disable compatibility mode since it is a SharePoint 2013 site and IE11 must run in compatibility mode to edit pages, but IE9 was behaving as you are showing. Setting the X-UA-Compatible to "IE=edge" in a meta tag did fix our issue, although setting the value to IE=10 did not affect our behavior. We also have the same doctype.