Does translating just the navigation but leaving the content untranslated lead to duplicate content SEO problems?

Question

Imagine there is a page with video, it has hreflang tags setup, to lead let's say German visitors to /de/ folder. So, on that German version of page, everything like menus, navigation and such are in German, but the video is the same, the title of the video (H1 tag) is the same, <title> and meta description is the same as on the original English page. It means that general (English) page and German version of it has the same key content in English.

To me it seems to be a SEO duplicate content issue. As I know, Google doesn't think that content is duplicate, if it is properly translated to other language.

Does my explained case mean that the content will be detected by Google as duplicate?

Answer 1

Google has a help page for multi language sites in which it states:

Translating only the boilerplate text of your pages while keeping the bulk of your content in a single language (as often happens on pages featuring user-generated content) can create a bad user experience if the same content appears multiple times in search results with various boilerplate languages.

The problem won't so much be duplicate content as it will be poor user experience when a German user searches something in German and lands on the page but can't consume the content. When a large portion of your site suffers from poor user experience like this, your entire site can get penalized for it. Google will notice when users back off your site and click on your competitors because of it.

Use robots.txt or a meta robots noindex tag to prevent Google from indexing untranslated content that has translated navigation.