Hreflang Linter — detect 7 common hreflang mistakes | SEO-GEO

What can you check or produce?

• Covers the 7 checks required by Google's localized-versions docs
• Accepts sitemap.xml, URL list, or single URL
• Each issue ships with a copy-paste fix template
• 1-click copy results as a Markdown ticket
• Completely free, no login required

How should you interpret results and choose the next action?

Google's localized-versions documentation requires hreflang annotations to be bidirectional, to use valid ISO 639-1 language codes and ISO 3166-1 Alpha-2 region codes, and recommends an x-default. Those are precisely the requirements international sites most often get wrong. We implement them as 7 auto-detectable checks — the grouping into 7 is 23SEOGEO's engineering choice, not a Google taxonomy. Source: https://developers.google.com/search/docs/specialty/international/localized-versions The 7 mistake classes: ① ISO code casing/region format (en-us vs en-US), ② missing x-default, ③ asymmetric return-links (A points to B but B doesn't point back), ④ missing self-referencing hreflang, ⑤ http/https mixing, ⑥ relative paths, ⑦ duplicated language declarations. These don't always trigger GSC warnings, but Google will silently drop the entire hreflang cluster. This tool fetches the submitted pages' <head> + sitemap, validates against all 7 rules, and outputs the issue list with official fix templates. Paste and go — no login.

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