Google might not crawl, index and rank "locale-adaptive" web pages. More details about the locale-aware crawl configurations of Googlebot can be found on the Google Support's website.
A page is "locale-adaptive" when the content that is being served is adapted based on the Accept-Language HTTP request header or the perceived location (IP address). This tool allows you to quickly see if a page is locale-adaptive.

Invalid URL
United StatesNo Proxy {{}}{{}}
URL Accept-Language Status Redirect Detected Language Page Title Meta Description H1 <html> lang Attribute Content-Language (meta http-equiv) Content-Language (HTTP Header) Vary: Accept-Language MD5
{{request.url}} {{request.accept_language}} {{request.status_code}} {{request.status_text}} {{request.redirect}} {{request.detected_language}} {{request.page_title}} {{request.meta_description}} {{request.h1}} {{request.html_lang}} {{request.html_content_language}} {{request.http_content_language}} {{request.vary_accept_language}} {{request.md5}}

Language Detection API

Daily requests: {{data.detectlanguage_api.requests_used}} / {{data.detectlanguage_api.requests_limit}}

Daily bytes: {{data.detectlanguage_api.bytes_used}} / {{data.detectlanguage_api.bytes_limit}}