Glossary
Hreflang
An HTML attribute that tells search engines which page version to show to users in different languages or regions.
Hreflang is a rel attribute added to the <link> tag in a page's <head> section or in HTTP headers and XML sitemaps. It signals to search engines the relationship between pages with identical or similar content intended for different language or geographic audiences. For example, an English page can use hreflang to point to its Spanish equivalent, French equivalent, and a default version for unspecified locales.
SEOs use hreflang to prevent duplicate content penalties, ensure the right version appears in search results for the right audience, and maximize crawl efficiency across language variants. Without it, search engines might rank the wrong page—serving English speakers the Spanish version, for instance—or split ranking signals across versions that should be treated as distinct.
Hreflang requires precision in implementation. Pages must reference each other bidirectionally (if page A points to page B via hreflang, page B should point back to A). The language codes must be valid ISO standards, and self-referential hreflang tags are common practice. Mistakes—wrong URLs, mismatched language codes, or missing reciprocal links—cause search engines to ignore the tags entirely, negating any benefit.