This task is part of WE6.4.4 Mobile domain sunsetting ([FY25-26 Q1](https://meta.wikimedia.org/wiki/Wikimedia_Foundation_Annual_Plan/2025-2026/Product_%26_Technology_OKRs#Q1)), as tracked by the parent task T214998.
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The hypothesis is as follows (emphasis mine):
> If we unify our domains by serving all page views on MediaWiki sites through a canonical domain, then we will reduce platform complexity and Search Engine Optimization (SEO) risks by eliminating the mobile-subdomain redirect. **Completion is measured by decreasing redirects for mobile visits on canonical domains from 100% to 0%.**
## Work
* [x] A week after the pilot rollout (T401595), review traffic on a pilot wiki and validate the basic working of the query and the change.
* [x] Decide on which wikis and wiki families of the main rollout (T403510) to check as milestones.
* [x] Write Hadoop query that measures the completion metric, and run it for July 2025 and August 2025 to set our baseline.
* [ ] During the main rollout (T403510), run it every few weeks for the week and report progress, looking for anything unexpected that might prevent us from reaching our target.
## See also
* SEO impact: T400022
* Performance impact, real-user metrics:
** Pre-rollout: [RFC: Mobile domain sunsetting 搂 Site speed](https://www.mediawiki.org/wiki/Requests_for_comment/Mobile_domain_sunsetting#Problem_4:_Site_speed), P73601
** Post-rollout: (TODO)
* Performance impact, synthetic testing: T403685