document.designMode controls whether the entire document is editable. Valid values are "on" and "off". According to the specification, this property is meant to default to "off". Firefox follows this standard. The earlier versions of Chrome and IE default to "inherit". Starting in Chrome 43, the default is "off" and "inherit" is no longer supported. In IE6-10, the value is capitalized. 

Syntax

var mode = document.designMode;
document.designMode = "on";
document.designMode = "off";

Example

Make an <iframe>'s document editable:

iframeNode.contentDocument.designMode = "on";

Specifications

Specification Status Comment
HTML Living Standard
The definition of 'designMode' in that specification.
Living Standard Initial definition.

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support Yes Yes Yes Yes Yes Yes
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support Yes Yes ? ? ? ? ?

See also