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

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidiOS SafariSamsung Internet
Basic supportChrome Full support YesEdge Full support YesFirefox Full support YesIE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile ? Firefox Android ? Opera Android ? Safari iOS ? Samsung Internet Android ?

Legend

Full support  
Full support
Compatibility unknown  
Compatibility unknown

See also