Visual diffs



A visual diff compares and shows differences between rendered (or displayed) documents, as opposed to showing the text (or markup) that is used to format such documents.

Since 2017, the main approach for visual diffs in MediaWiki is the (pictured) provided by the  extension, which compares the HTML of two documents. It provides visual diffs in VisualEditor's editing preview, as well as (still as a beta feature) in MediaWiki's standard diff display.

Previous attempts at visual diffs in MediaWiki include:
 * As part of their testing efforts, the team created the "" tool (released around April 2016), which is a pixel differ of the page rendered as an image, used to identify differences between Parsoid and the legacy parser.
 * [http://sourceforge.net/projects/weha/ Wiki Edit History Analyzer] was another apparently-abandoned attempt at visual diffs; its development was discussed in the 2010 paper "What Did They Do? Deriving High-Level Edit Histories in Wikis".
 * As part of  2008,  (mentored by ) created, which was later removed in 2009.