Free tool

Hreflang validator

Paste any URL. We fetch it, parse the hreflang block in <head>, check BCP 47 codes, and try the return-link from each declared alternate. No email gate.

We fetch the page and follow up to 10 declared alternates to check return-link mismatches. About 5 to 20 seconds.

Fetching and validating hreflang...

Findings

Declared alternates

hreflangURLHTTPReturn link

What we check

BCP 47 language codes

Each hreflang attribute must be a valid BCP 47 language tag (en, en-US, zh-Hant, x-default and so on). Bad codes silently fail at Google.

Self-reference

The page being validated should declare itself among the alternates. Missing self-reference is the second most common hreflang mistake.

Return-link consistency

If page A declares page B as its alternate for language X, page B should declare page A back. Asymmetric hreflang is the most common cause of Google ignoring the block entirely.

x-default

If you have an x-default declaration we check that it's well-formed and reachable. x-default is optional but recommended for sites with a language picker.

What this tool doesn't do

We don't parse HTTP-header hreflang or sitemap hreflang in this MVP. We don't render JavaScript, so SPA sites that inject hreflang client-side will look empty. Hosted full-crawl validation is part of an on-page audit.

Need this at scale?

For sites with multiple languages across thousands of URLs, this is part of our technical SEO audit, including HTTP-header and sitemap-level checks.