CSS and layout compatibility changes

Recent versions of Internet Explorer have changed the behavior of some CSS and layout features to better support modern standards and to ensure consistency with other popular browsers. Here, you'll find out how this can affect your older websites and what to do.

In this section

Topic Description

Checkbox and radio button layout defaults

To provide better consistency with other browsers, the default values for a number of layout properties have changed for checkbox and radio button controls in IE11 edge mode.

Default font changes

We are updating the Document Object Model (DOM) default fonts and UI fonts for Windows apps using JavaScript for several languages, as defined in the table below.

Flexible box ("Flexbox") layout updates

With Microsoft Edge, you can update your sites to match the latest Flexbox standard and simplify cross-browser code.

Font sizing for Thai and East Asian text

Thai and East Asian text may look smaller in Windows Internet Explorer 9 than in Windows Internet Explorer 8 and earlier releases.

Rounded corners and legacy gradient filters

When you use legacy gradient filters to fill elements that have had their corners rounded using the border-radius property, the gradient bleeds past the border of the element. Here's how to prevent this from happening.

Stylesheet titles are readonly

In IE8 Standards mode and below you can change the value of a styleSheet object's title. In IE9 Standards mode mode the write command will be ignored and the original value will remain.

Text layout and natural metrics

For text layout in IE9 mode (and later), Internet Explorer 9 uses natural metrics instead of the Windows Graphics Device Interface (GDI) metrics that other Windows browsers use.

ActiveX controls and plugin changes

Browser features and compatibility changes

HTML and DOM compatibility changes

JavaScript compatibility changes

Legacy feature support changes

Internet Explorer compatibility changes by version