Hreflang Tester: Catch every error.
Free hreflang tester for international SEO. Validate return links, detect missing x-default, flag wrong language codes, and fix asymmetric hreflang across your multi-regional site.
Why hreflang is the trickiest tag in technical SEO
Hreflang exists to tell Google which language and region each version of a multi-locale page targets. Implemented correctly, it makes Google show the right version to the right user — German users get the .de page, French users get the .fr page, English users get the canonical English page. Implemented incorrectly, every locale fights every other locale for the same query, and Google often shows none of them.
What our hreflang tester validates
- Return-link symmetry — every hreflang declared on Page A must be matched by an equivalent declaration on Pages B, C, D pointing back. Asymmetric hreflang is invalid and ignored entirely.
- Self-reference — every page should declare its own hreflang. Skipping it is a frequent oversight that breaks the cluster.
- Language and region codes — must use valid ISO 639-1 (language) and ISO 3166-1 alpha-2 (region) codes.
en-ukis invalid; the correct code for the United Kingdom isen-gb. - x-default declaration — should point at the fallback page for users who don’t match any specific locale. Missing x-default is a common cluster bug.
- HTML vs XML implementation — hreflang can live in
<link rel="alternate">tags or in the sitemap. Using both with mismatched declarations is a self-conflict. - Pointing to indexable pages — hreflang to a 404 or noindexed page invalidates that branch of the cluster.
Multi-regional sites we’ve worked with
Hreflang complexity scales fast with locale count. Two locales (en-us + en-gb) is easy. Twelve locales — the typical mid-market e-commerce expansion — means each page needs 12 hreflang declarations, and every page in every locale needs to match. Our tester handles clusters of any size and identifies the specific pages where the cluster breaks.