hreflang guides

• x-default: what the value does and where to point it
  How Google uses hreflang x-default, when a cluster needs one, and which URL makes the best fallback.
• en-UK or en-GB: the United Kingdom in hreflang
  Why hreflang="en-UK" has no effect in Google Search and en-GB is the correct code for the United Kingdom.
• es-419 and other codes Google does not support
  UN M.49 region codes like es-419 are valid BCP 47 but Google ignores them in hreflang. What to use instead.
• Why Google ignores hreflang
  The common causes of hreflang being ignored: missing return links, non-canonical targets, redirects, invalid codes and conflicting methods.
• HTML head, HTTP header or sitemap: choosing one hreflang method
  The three ways to declare hreflang, what each suits, and why a cluster uses only one.
• The wrong country version ranks despite correct hreflang
  Why Google shows a different country version than hreflang suggests, and what to check.
• How long hreflang takes to work
  hreflang changes apply when Google recrawls every page in the cluster. What decides the delay.
• hreflang return links explained
  Why every page in an hreflang cluster lists every other page, including itself.
• hreflang on WPML, Weglot, Shopify and next-intl
  Known hreflang problems on popular platforms and how to spot them.
• hreflang API
  REST API for hreflang cluster checks and code validation. JSON in and out, free, rate limited.
• hreflang MCP server
  Connect Claude, Cursor, VS Code and other MCP clients to hreflang checks over Streamable HTTP.