From mediawiki.org
MediaWiki extensions manual
Release status: stable
Implementation User interface
Description Provides an interface for migrating article text to new versions of the MediaWiki parser
Latest version Continuous updates
Compatibility policy Snapshots releases along with MediaWiki. Master is not backward compatible.
MediaWiki 1.41+
PHP 7.4+
Database changes No
License Creative Commons Zero v1.0 Universal
Help Help:Extension:ParserMigration
  • $wgParserMigrationEnableQueryString
Quarterly downloads 0
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Issues Open tasks · Report a bug

The ParserMigration extension was introduced in gerrit:296182. It provides an interface for comparing article rendering with a new non-default version of the MediaWiki parser thus serving as a parser migration tool.

It was deployed on the Wikimedia production cluster until 2018 to compare Tidy-based output with a RemexHTML-based output. RemexHTML was the replacement for Tidy. In 2023 it was redeployed in order to compare legacy wikitext parser output with output generated by the Parsoid wikitext parser.

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

Using the extension[edit]

See Help:Extension:ParserMigration and the extension's README file.


  • Download and place the file(s) in a directory called ParserMigration in your extensions/ folder.
  • Add the following code at the bottom of your LocalSettings.php file:
    wfLoadExtension( 'ParserMigration' );
  • Yes Done – Navigate to Special:Version on your wiki to verify that the extension is successfully installed.

See also[edit]

For the 2018-era deployment of the ParserMigration tool, see: