What is hreflang? Multilingual SEO Explained

Definition

hreflang is an HTML attribute that tells search engines which language and (optionally) region a page is intended for. It is used to link together alternate versions of the same content — for example an English page and its French translation — so search engines can serve the right version to users based on their language and location.

Three ways to declare hreflang

• HTML <link> tags in the <head> of each page.
• HTTP headers (useful for non-HTML files like PDFs).
• XML sitemap entries with <xhtml:link rel="alternate"> nodes.

Common mistakes

• Missing return tags — every page in the cluster must reference every other version, including itself.
• Wrong language or region codes — use ISO 639-1 for language and ISO 3166-1 Alpha 2 for region (e.g., en-GB, not en-UK).
• Conflicting canonical tags — the canonical of each language version should point to itself, not to the original-language master.
• Pointing hreflang to redirects or 404s — destination URLs must return 200.

hreflang is finicky but essential for international SEO. After implementing it, validate with Google Search Console's International Targeting report and scan your site to make sure none of the alternate URLs are broken.