Why it matters
Switching languages with cookies or by swapping content in place makes the versions very hard for Google to handle. Googlebot mostly crawls from US IP addresses without an Accept-Language header, so content that adapts to the visitor's location or language may never be crawled in its other versions.
How to meet it
Give each version its own URL (example.de, de.example.com or example.com/de/), never a ?lang= parameter or a cookie. The URL alone decides the language and region served; a remembered choice may only preselect the language selector, never change the content of a URL.
How to test it
curl each version's URL from one location with no Accept-Language header and no cookies: each returns its own language and content.
How Regensbot covers it
Decided from one URL.
An audit reads the response, the headers, the HTML, robots.txt, the sitemaps and the structured data, and the finding shows the evidence it saw.
Sources
Google documents03
- 01Managing multi-regional and multilingual sitesGoogle Search Central (opens in a new tab)
- 02How Google crawls locale-adaptive pagesGoogle Search Central (opens in a new tab)
- 03Tell Google about localized versions of your pageGoogle Search Central (opens in a new tab)
Claims in the knowledge base04
- D2-C560ConfirmedFocusing on Internationalisation and LocalisationSaid on stage
- D2-C561SourceFocusing on Internationalisation and LocalisationGoogle's documentation
- D2-C562ConfirmedFocusing on Internationalisation and LocalisationShown on screen
- D2-C595SourceFocusing on Internationalisation and LocalisationGoogle's documentation
Claim IDs refer to the Search Central Live 2026 knowledge base. The knowledge base (opens in a new tab)
- Confirmed
- Google's documentation states the same thing.
- Source
- The claim is the cited document itself.