Manual:$wgEnableHtmlDiff

Miscellaneous settings: $wgEnableHtmlDiff
Whether to allow visual comparison in diffs.
Introduced in version:1.14.0 (r39406)
Removed in version:1.16.0 (r58267)
Allowed values:(boolean)
Default value:false

DetailsEdit

Whether to allow visual comparison in diffs (requires PHP 5.2).