Manual:$wgLivePreview/de-formal

<translate> This feature was removed completely in version <tvar name=ver>1.17.0</tvar>.</translate>

<translate> Miscellaneous settings</translate>: $wgLivePreview
Experimental preview feature to fetch rendered text over an XMLHttpRequest from JavaScript.
<translate> Introduced in version:</translate>	1.5.0
<translate> Removed in version:</translate>	1.17.0
<translate> Allowed values:</translate>	(boolean)
<translate> Default value:</translate>	`false`
<translate> Other settings:</translate> <translate> Alphabetical</translate> \| <translate> By function</translate>

Details

Experimental preview feature to fetch rendered text over an XMLHttpRequest from JavaScript instead of forcing a submit and reload of the whole page.

The configuration toggle was removed in 1.17.0. Now live preview is always enabled (though it still depends on the uselivepreview user preference).