Free tool
Hreflang checker
Buyers ask AI assistants questions in their own language, and assistants answer with sources in that language. Hreflang is how you tell machines which version of a page serves which audience. Enter a URL and this checker lists every declared alternate, verifies the page references itself, and confirms an x-default exists. Broken clusters are how the wrong version, or a rival, gets surfaced.
Multilingual AI visibility runs through hreflang
A German buyer asking ChatGPT for recommendations gets a German answer built from German sources. If your German page exists but machines cannot connect it to your English one, the retrieval layer treats them as unrelated documents: signals stay split, the weaker page competes alone, and the answer may quote a competitor's local page or paraphrase your English one badly. Hreflang stitches your language versions into one cluster so each market is served by the page you built for it.
The mechanism lives in the search layer, and that is exactly the layer that matters, because assistants that browse ground their answers on search indexes. Gemini draws on Google's index, and ChatGPT search leans on comparable retrieval infrastructure, so the language mapping those indexes hold is the mapping AI answers inherit. Getting hreflang right for Google and Bing is simultaneously getting it right for every engine that reads them, which makes this one of the few classic SEO chores that pays out twice.
Losing a market quietly is the failure mode
The damage from a broken cluster rarely announces itself. Your English pages keep performing, dashboards look normal, and the Spanish or Japanese buyer simply gets an answer built from someone else's pages. Because the loss happens in a language your team may never search in, it persists for quarters. Auditing the cluster page by page is the only way to see it, which is what this tool is for.
How to read your results, and what to fix first
The report lists each declared alternate with its language and optional region code. Three checks matter most. Self-reference: the page must include itself in its own alternate list, and a cluster missing self-references is commonly ignored. Reciprocity: every alternate must link back, since one-directional annotations get discarded, though this tool reads one page at a time, so spot-check a partner page too. x-default: the entry that catches every unmatched language, usually pointing at your language picker or your primary version.
Fix order is mechanical. Add the missing self-reference first, then the missing x-default, then repair invalid codes, since en-UK silently fails where en-GB works, and language must use ISO 639-1 with an optional ISO 3166-1 region. Use absolute URLs throughout. After the cluster is clean, the remaining question is whether each market's assistants actually name you, and Reachroller tracks brand mentions across ChatGPT, Claude, Gemini, Perplexity and Grok from $29 per month with a free 3-day trial.
Frequently asked questions
What is x-default and do I really need it?+
x-default names the page a machine should choose when the visitor's language matches none of your declared alternates. Point it at your language selector or your primary market's version. You can ship a valid cluster without it, but leaving it out means engines guess for every unmatched locale, and adding one line per cluster removes the guess.
Do AI engines actually use hreflang?+
Indirectly and reliably. Hreflang is a signal for search indexes, and assistants that answer live questions ground on those indexes: Gemini reads Google's, ChatGPT search and Copilot lean on Bing-style retrieval. When the index knows which URL serves which market, the assistant retrieving sources for a French question finds your French page. A broken cluster breaks that chain at the first link.
Does every page need hreflang annotations?+
Only pages that exist in more than one language or regional variant. A single-language site can skip the whole subject. Where translations do exist, every member of the group needs the full annotation set, including itself, because clusters are validated per page and one incomplete member weakens the group. Templates should emit the annotations automatically rather than relying on editors.
Hreflang tags or sitemap annotations, which is better?+
Both work, and machines treat them equally, so choose on maintenance cost. Link tags in the head are easy to inspect and debug page by page, which is what this tool reads. Sitemap annotations keep the HTML lean and centralize the mapping, which scales better past a few languages. Pick exactly one method, since running both invites contradictions.
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