Parsoid/Parser Unification/Migration

Wikitext is the markup language used by editors on Wikimedia projects, and Parsoid is the Wikimedia Foundation's next-generation wikitext parser. Parsoid has been used internally for editing tasks since 2012, but in 2024 as part of the Parser Unification project the Wikimedia Foundation began to use Parsoid to generate HTML for browsers. In most cases, there should be no visible change to readers.

This page links to further documentation on Parsoid and the transition process to help editors understand the changes being made.

What has changed

In November 2023 a user preference was added to allow individual users to opt-in to using the new Parsoid parser for all pages, using the ParserMigration extension. The process to opt-in (or opt-out) is described on the help pages for the ParserMigration extension.

In February 2024 some wikis began to use the new Parsoid wikitext parser for certain pages by default. A user notice informed readers the first time they encountered a page rendered with Parsoid, and at intervals afterward, directing them to this page for additional information. Any page rendered with Parsoid has a Use legacy parser link in the user tools sidebar allowing users to switch back to the old parser for that page in the event of any issues. In addition, the user preference added by the ParserMigration extension can be used to permanently opt-out of the use of Parsoid to render pages.

Help, something broke! Was it Parsoid's fault?

Please consult the Parsoid Known Issues page, which describes some differences that may occur between the legacy parser output and Parsoid, as well as provides links to verify that Parsoid is (or is not) at fault, and to report any issues you discover.