Search optimisation
hreflang validity
If hreflang exists, codes are valid and return links reciprocate
What we check
If hreflang exists, codes are valid and return links reciprocate
Why it matters
Invalid language codes are ignored, so the wrong regional page can show.
How to fix it
Use valid ISO codes and add reciprocal hreflang links.
How it affects your score
This check sits in Search optimisation, which is worth 25% of the overall score. A critical result costs the full weight of the check; a warning costs half. If we can't measure it on your page, we leave it out of the score entirely.