Hreflang is an HTML link attribute that specifies the language and optional regional targeting of a web page. It helps search engines serve the correct language version of a page to users based on their language preferences and geographic location. The attribute is implemented using link tags with rel="alternate" and the hreflang value.
Hreflang is essential for multilingual websites that serve the same content in different languages. Without hreflang, search engines might index the wrong language version or treat translated pages as duplicate content. The attribute creates a bidirectional relationship: each language version must reference all other versions, including itself. International SEO books on Amazon cover implementation patterns.
For URL shortening services that operate in multiple languages, hreflang ensures that search engines display the appropriate language version of the service's pages. The glossary page you are reading now, for example, uses hreflang to connect its Japanese, English, and Chinese versions.
Common hreflang mistakes include missing self-referencing tags, incomplete bidirectional references, incorrect language codes, and conflicts with canonical URLs. Google Search Console reports hreflang errors, making it an essential monitoring tool. Search Console books on Amazon discuss diagnostic approaches.