Extension:ParserMigration

The ParserMigration extension was introduced in 296182. It provides an interface for comparing article rendering with a new non-default version of the MediaWiki  thus serving as a 2>Special:MyLanguage/Parsing/Replacing Tidy|parser migration tool.

It was deployed on the Wikimedia production cluster until 2018 to compare Tidy-based output with a RemexHTML-based output.  is the replacement for Tidy.

The availability of the tool can be controlled by a user via the "parsermigration" preference option.