What does the hreflang check look for?
It checks that your hreflang annotations correctly connect your language and region variants. Specifically:
- Valid codes — hreflang values use correct language and region codes (e.g.
en-GB,fr-CA). - Reciprocity — each language version links to the others and they link back (the return-link requirement).
- x-default — an
x-defaultis provided for users who don't match a specific version. - Self-reference — each page includes an hreflang entry for itself.
Correct, reciprocal hreflang passes; some issues (missing return links or x-default) is a warning; broken or non-reciprocal hreflang is a fail.
How is it evaluated, and how is it scored?
GEObubbly checks the page's hreflang annotations for valid codes and reciprocity. It's an extended International SEO check that runs partially, since verifying reciprocity involves checking the linked versions.
Why hreflang and reciprocity matter for SEO and GEO
When you have the same page in multiple languages or regional variants, hreflang annotations tell engines which version to show which users — English to English speakers, the Canadian-French version to users in Quebec, and so on. Done right, this ensures people land on the version meant for them and prevents your language variants from being treated as duplicate content competing with each other. But hreflang is notoriously easy to get wrong, and it has a strict rule: reciprocity. If page A says page B is its French version, page B must point back to A — return links must be mutual, or engines ignore the annotation. Each page should also reference itself in the set, use valid language/region codes, and ideally provide an x-default for users who don't match any specific version. Broken, one-way or mis-coded hreflang leaves engines to guess, so users get served the wrong-language page — a poor experience that wastes your localisation effort. The fix is to ensure every variant is mutually linked with correct codes and a self-reference. For GEO, correct hreflang helps AI engines serve and cite the right language version of your content to the right users. It's central to International SEO.