1.8 URL structure & internationalisationHighVerified
Invalid hreflang language/region code
hreflang uses ISO language and optional region codes. A wrong code, for example a country code where a language is expected, makes the annotation invalid and ignored.
What it is
Wrong ISO codes.
Why it matters
Invalid annotations are ignored.
How to fix it
Use valid ISO 639-1 language + ISO 3166-1 region codes.
How to find it on your site
- List the hreflang values in use.
- Validate each against ISO 639-1 language and ISO 3166-1 region codes.
- Correct any invalid combinations, such as en-UK which should be en-GB.
- Re-validate the set.
Cross-reference to ranking and citation factors
An invalid code is dropped, so that version loses its routing signal. Correct codes are essential for hreflang to apply.
Impact
Medium-high. Direct.
Evidence
Use valid language/region codes for hreflang. Google Search Central, Tell Google about localized versions (hreflang)
Sources