When a URL is associated with several different incoming hreflang annotations, it presents a conflict.
Why is this important?
Search engines use hreflang tags to understand how to index language-specific page versions. For instance, if the English version of a webpage lists its French variant via hreflang, the search engines will index both pages, recognizing their language-specific equivalents.
Let's refer to the French page, which receives an incoming hreflang tag from the English version, as possessing incoming hreflang. Now, if a German version also points to the French page via hreflang but labels it as Spanish, it results in a discrepancy.
Such unclear instructions can lead search engines to discard the hreflang annotations altogether.
What does the Optimization check?
This Optimization is triggered by any URL that receives inconsistent hreflang annotations from several different URLs.
Remark: This Optimization bears resemblance to another: "Has conflicting outgoing hreflang annotations." The key distinction lies in the focus—this Optimization concerns the target of an hreflang annotation (incoming), whereas the other pertains to the source page of the hreflang (outgoing).
Examples that trigger this Optimization:
Evaluating the URL: https://example.com/fr/page-a/
Conflicting hreflang would be detected if the page possesses incoming annotations like so:
<link rel="alternate" href="https://example.com/fr/page-a/" hreflang="fr-fr" />
and if it simultaneously carries an inconsistent incoming hreflang like the following:
<link rel="alternate" href="https://example.com/fr/page-a/" hreflang="es-es" />
How do you resolve this issue?
In such cases, it can be difficult for search engines to pinpoint the root of the error. Humans, with their linguistic knowledge, should find it easier to discern.
To correct these mismatches, review the hreflang annotations to identify the inaccurate ones. Then, manually adjust the URLs to rectify the errors, or amend the script generating the hreflang, depending on your website's framework.
The goal is to establish a uniform set of hreflang annotations across your website, ensuring all references are consistent with their designated language pages.