🌐 Hreflang Checker

What does the hreflang checker validate?

After you implement hreflang tags using a generator or a CMS plugin, you need a way to verify the live result is correct. This tool fetches the page server-side — bypassing any CORS restrictions — and runs four key checks that mirror how Google validates international SEO annotations.

1. Language code validation

Every hreflang attribute must use a valid BCP 47 language tag: a two- or three-letter ISO 639-1 language code (e.g. en, fr, de), optionally followed by a hyphen and an ISO 3166-1 Alpha-2 country code (e.g. en-gb, fr-ca, zh-cn). Common mistakes include en-uk instead of en-gb, or zh when you mean zh-cn. Invalid codes are silently ignored by Google.

2. x-default check

x-default is a special hreflang value that designates the fallback page for users whose locale matches none of your language variants. It is optional but recommended by Google for any site with a language-agnostic home page or selector. The checker flags its absence as a warning.

3. Self-reference check

Every page in an hreflang set must include a tag pointing to itself. A missing self-reference is a common implementation error — the page's own URL must appear in the set alongside all the other language variants.

4. Reciprocal link check

The reciprocal rule is the most commonly broken hreflang requirement. If your English page references the French page, the French page must reference the English page back. The checker fetches up to six of your alternate URLs and confirms each one contains a link back to the page you submitted. Failures here are errors, not warnings — Google will discard the whole annotation cluster if reciprocity is broken.

Why use a server-side proxy?

Browser-based tools can only fetch pages that return permissive CORS headers. Because most websites do not allow arbitrary cross-origin requests, a browser-only checker would fail on nearly every real-world URL. This tool sends the fetch request from the server, just like a search-engine bot would, so you get the real HTML the crawler sees.

Limitations to be aware of

• JavaScript-rendered tags — the checker reads the raw HTML, not the post-JavaScript DOM. If your framework injects hreflang tags via client-side rendering (some React or Angular setups), they will not appear here. Use SSR or static generation to make hreflang visible to crawlers.
• Bot-blocked pages — some sites block non-browser requests. If the page returns a 4xx or 5xx error, the checker reports it but cannot inspect the HTML.
• Large language sets — the reciprocal check fetches up to six alternate pages to keep results fast. For sites with many languages, verify the remaining pages manually or run the checker from each variant's URL.

How to fix common hreflang errors

Missing reciprocal links

Paste the same complete hreflang block into every language variant. The Hreflang Tag Generator outputs the full set — copy the identical block to every page in the language cluster.

Invalid language code

Replace the invalid code with a correct BCP 47 tag. Use en-gb not en-uk, zh-cn for Simplified Chinese, zh-tw for Traditional. Check the full list of codes in the generator.

Missing self-reference

Add a <link rel="alternate" hreflang="en" href="https://example.com/en/" /> tag on the English page pointing to itself (replace with your own language and URL).

Missing x-default

Add <link rel="alternate" hreflang="x-default" href="https://example.com/" /> pointing to your language-neutral home page or language selector on every page in the set.