Build output has canonical link linking to the same URL as another alternate link, leading to SEO issues

[WaldemarEnns]

Environment

❯ npx nuxi info
Working directory: /home/projects/github-q5ddsy                                17:08:17
Nuxt project info:                                                             17:08:17

------------------------------
- Operating System: Linux
- Node Version:     v18.20.3
- Nuxt Version:     3.13.1
- CLI Version:      3.13.1
- Nitro Version:    2.9.7
- Package Manager:  [email protected]
- Builder:          -
- User Config:      compatibilityDate, devtools, modules, pages, routeRules, i18n
- Runtime Modules:  @nuxtjs/[email protected]
- Build Modules:    -
------------------------------

                                                                               17:08:17
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👉 Read documentation: https://nuxt.com

Reproduction

Reproduction here:

https://stackblitz.com/edit/github-q5ddsy-62oh2a?file=.output%2Fpublic%2Findex.html

Summary: Using nuxt-i18n with a default language and a translated language

Describe the bug

Please check the output index.html at

• either live in your browser
• build the project with npx nuxt build --preset github_pages

Take a look at the auto-generated <link> elements, especially the rel="alternate" & red="canonical":

<link id="i18n-alt-en" rel="alternate" href="https://example.com/en" hreflang="en">
<link id="i18n-alt-en-US" rel="alternate" href="https://example.com/en" hreflang="en-US">
<link id="i18n-alt-de" rel="alternate" href="https://example.com" hreflang="de">
<link id="i18n-alt-de-DE" rel="alternate" href="https://example.com" hreflang="de-DE">
<link id="i18n-xd" rel="alternate" href="https://example.com" hreflang="x-default">
<link id="i18n-can" rel="canonical" href="https://example.com">

Notice, that the same URL https://example.com is being referred to, from:

<link id="i18n-xd" rel="alternate" href="https://example.com" hreflang="x-default">
<link id="i18n-can" rel="canonical" href="https://example.com">
<link id="i18n-alt-de" rel="alternate" href="https://example.com" hreflang="de">

That leads in SEO indexing/crawling, to an issue:

• Bing Webmaster tools are complaining about the canonical link, referring to a link that is already marked as an alternative translation
• Google Search Console is complaining about the same issue

URL that I requested indexing for: https://waldemarenns.de/

Bing Webmaster Tools:

URL cannot be indexed by Bing
The URL is not indexable as the page is an alternate version of the similar page which you have specified as canonical version using a <link rel="canonical"> tag. Bing does not index the alternate version.
Canonical URL :https://waldemarenns.de/en

Screenshot:

Google Page Speed Insights:

Document does not have a valid rel=canonicalPoints to another `hreflang` location (https://waldemarenns.de/)

Screenshot:

Take a look: https://pagespeed.web.dev/analysis/https-waldemarenns-de/30jj8518lg?form_factor=desktop

ℹ️ Feel free to inspect my site that is mentioned.

Additional context

Refers to #2925

Logs

No response

[memic84]

We have the same issue. Just check the head of https://orakel.com/ and you'll see duplicate alternate link for the i18n Link.