Hreflang is the most error-prone part of international SEO. Run a free hreflang check the way search engines do - across your whole multilingual site - and see exactly what's broken. Paste a URL below for an instant check, no account needed.
Instant, free, no account needed - homepage checked on the spot.
We run 10+ products in 15+ languages, so we built deep hreflang validation most tools don't bother with.
Page A links to B, but B doesn't link back - the #1 hreflang error.
An hreflang declares a language the target page isn't actually in.
Hreflang annotations pointing at dead or redirected pages.
Pages that forget to include an hreflang tag for themselves.
Hreflang pointing at non-canonical URLs, confusing search engines.
Missing html lang attributes and hreflang groups that aren't fully crawled.
Confirm ownership with DNS, a meta tag, or a file upload.
We collect every hreflang annotation and build your full language graph.
Resolve missing reciprocals, mismatches, and broken targets, then re-run.
Hreflang is the most error-prone area of technical SEO. Get these right and Google serves the correct language/region version to each user.
If page A points to page B with hreflang, page B must point back to A. Google ignores one-way hreflang entirely. Every annotated page in a cluster must reference every other version, including itself.
Each page must include an hreflang tag pointing to its own URL with its own language code. Leaving out the self-reference is one of the most common reasons a whole cluster is silently ignored.
Use ISO 639-1 language codes and optional ISO 3166-1 Alpha-2 region codes - e.g. en, en-GB, pt-BR. Common errors: using en-UK (it's en-GB), or a region code with no valid language. Add x-default for your fallback/selector page.
Every hreflang URL must return a live 200 - not a redirect, not a 404, and it must be the canonical version of that page. Hreflang pointing at a redirected URL breaks the mapping.
The page's <html lang="…"> should match the language you claim in hreflang. A mismatch sends conflicting signals to crawlers and assistive tech. Keep the markup, hreflang, and actual page content all in agreement.
Want the full background? Read our hreflang tags guide and the wider localization SEO guide.
When you check hreflang online with Kalenux, every flagged issue tells you the page, the language group it belongs to, and exactly what to change. Here is how to act on the most common findings.
Open the alternate page it should link back to and add the reciprocal hreflang annotation. Both pages must reference each other and themselves. Re-run the check and the whole group clears at once.
The annotation points at a URL that no longer returns 200. Update it to the live, canonical URL of that language version. Never point hreflang at a redirect chain.
Your hreflang points at a URL that is canonicalised elsewhere. Point it at the canonical URL instead, so hreflang and canonical agree.
Swap the code for a valid ISO 639-1 language (plus optional ISO 3166-1 region), e.g. change en-UK to en-GB. Add an x-default for your language selector or fallback page.
A return-tag (reciprocal) error happens when page A declares an hreflang link to page B, but B does not link back to A. Search engines require the references to be mutual, so a missing return tag invalidates the relationship. It is the most common hreflang mistake, and we flag every instance.
Add and verify your site, then run a crawl. We collect the hreflang annotations on every page, build the full language graph, and validate each group the way a search engine does - reporting missing reciprocals, language mismatches, and broken targets across all your locales at once.
Yes. Each page in an hreflang group should include a tag pointing to itself alongside its alternates. Missing self-references are a frequent cause of search engines ignoring the whole group, so we flag pages that omit them.
Hreflang must reference canonical, indexable URLs. Pointing it at non-canonical or redirected pages sends conflicting signals and the annotations are discarded. We detect hreflang targeting non-canonical URLs so you can correct them.
Yes. You can check hreflang online on any URL instantly with no account. The free check looks at the page you paste; create a free account to run a full-site hreflang check that validates every language group across your whole domain.
Yes. It runs in your browser - paste a URL and get results on the spot. There is nothing to download and no crawler to configure for the instant check.
Checking hreflang manually means opening every page, reading its annotations, and cross-referencing each alternate to confirm the references are mutual and the targets are live and canonical. We build the full language graph for your site and validate every group automatically, so you find the one broken reciprocal among thousands of tags in seconds, not hours.
Crawl-based checks across indexability, canonicals and more.
Find every broken internal and outbound link on your site.
Measure load performance per page, mobile and desktop.
Free while in beta. Create an account and start auditing.
Free to start. Validate hreflang across your whole multilingual site.
Check hreflang now