10 Duplicate content and international sites
Duplicate content issues can arise when you provide the same content translated into different languages, but available on different URLs. This is generally not a problem as long as the content is for different users in different countries. While we strongly recommend that you provide unique content and avoid changing the meaning of your content from one language to another, we know that’s not always possible.
To differentiate between the different language versions of the page and serve the correct language or regional URL to searchers, follow the guidelines on rel-alternate-hreflang. Without using hreflang your content may lose value and make it harder to pull traffic.
If you disallow crawling in a robots.txt file or by using a ‘noindex’ robots meta tag, there’s no need to hide the duplicates. However, if you're providing the same content to the same users on different URLs (for instance, if both example.de/ and example.com/de/ show German language content for users in Germany), you should pick a preferred version and redirect (or use the rel=canonical link).