hreflang
Also called: hreflang tags, hreflang tag, hreflang attribute, rel alternate hreflang
Hreflang is an HTML annotation (rel="alternate" hreflang) that tells search engines which language or regional version of a page to serve a given user. It signals variants like en-US, en-GB, or de-CH so Google shows the right localized page instead of the wrong one.
How hreflang works
You declare each alternate version with a link annotation. In the page <head>:
<link rel="alternate" hreflang="en-us" href="https://example.com/us/" />
<link rel="alternate" hreflang="en-gb" href="https://example.com/uk/" />
<link rel="alternate" hreflang="x-default" href="https://example.com/" />You can serve the same map three ways: HTML link tags, an HTTP Link header, or xhtml:link entries in an XML sitemap. Language codes follow ISO 639-1 (en, de), regions follow ISO 3166-1 Alpha 2 (US, GB), so en-GB means English for the UK. Reserved codes like UK or EU are invalid, and x-default catches users no version matches.
Two rules make or break it. Every version must list itself (self-reference) and every version must link back to the others (return tags). If page X points to Y but Y does not point back, Google may ignore the annotation. Targets that 404, redirect, or carry noindex get dropped too.
hreflang is a signal, not a directive. It does not push a page up the rankings; it decides which existing version shows to a searcher, so a German user lands on the German URL instead of the US one. Pages in a cluster can also consolidate duplicate-content signals when the same language serves several regions (en-US vs en-GB).
How it affects your traffic
If you run country or language variants, misfired hreflang quietly costs traffic: the wrong URL ranks in the wrong market, near-duplicate pages cannibalize each other, and click-through drops when a US searcher lands on a GBP-priced page. It is fiddly at scale because every added market multiplies the return-link matrix, and one broken or non-reciprocal tag can void an entire cluster. Our Technical SEO work audits and generates the full annotation set, validates language and region codes plus reciprocal links, and watches for drift after each deploy.
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