Hreflang tags

Hreflang tags tell search engines which language/region version of your content to serve in which country. They're easy to understand, easy to implement, and stunningly easy to get wrong.

What they do

Suppose you have three versions of a page:

• example.com/us/product. US English
• example.com/uk/product. UK English
• example.com/fr/product. French for France

Hreflang tells Google: show the US version to users in the US, UK version to UK users, French version to French users. Without hreflang, Google guesses (often wrongly).

The syntax

Each page references every version (including itself). Three implementations, pick one:

1. HTML head tags (most common)

<link rel="alternate" hreflang="en-us" href="https://example.com/us/product" />
<link rel="alternate" hreflang="en-gb" href="https://example.com/uk/product" />
<link rel="alternate" hreflang="fr-fr" href="https://example.com/fr/product" />
<link rel="alternate" hreflang="x-default" href="https://example.com/us/product" />

2. HTTP headers (for non-HTML files)

Link: <https://example.com/us/product>; rel="alternate"; hreflang="en-us"

3. XML sitemap

<url>
  <loc>https://example.com/us/product</loc>
  <xhtml:link rel="alternate" hreflang="en-us" href="https://example.com/us/product"/>
  <xhtml:link rel="alternate" hreflang="en-gb" href="https://example.com/uk/product"/>
  ...
</url>

Valid language/region codes

• Language only: en, fr, es, de (ISO 639-1)
• Language-region: en-us, en-gb, en-au, fr-ca (ISO 3166-1 alpha-2 for region)
• Special: x-default (the fallback for unmatched users)

x-default

The x-default tag specifies a fallback version for users whose language/region doesn't match any specific hreflang. Usually your US English or international-English version.

Common mistakes

• Non-reciprocal references. If page A links to page B with hreflang, page B must link back to A. One-way hreflang is silently ignored.
• Missing self-reference. Every page must include itself in its hreflang set.
• Wrong region codes. "en-uk" is invalid, use "en-gb". "es-mx" is valid (Mexico); "es-es" is Spain.
• Using language tag for region intent. hreflang="en" means "any English", you can't say "English except UK."
• Canonical conflict. If your French page canonicals to the English page, your hreflang is undermined.
• Noindex on a language version. Again, conflicts.

The implementation nightmare

For a site with 10 languages × 20 countries = 200 page variations, every page needs 200 hreflang references. This gets unmaintainable fast in head tags. For large sites, XML sitemap hreflang is the sanity-preserving choice.

Testing

• Google Search Console → International Targeting report, shows errors
• Merkle hreflang tool, checks reciprocation for specific URLs
• Screaming Frog, has an hreflang audit in the Pro version
• Sitebulb, excellent hreflang visualization

When NOT to use hreflang

• If you only have one language/region, you don't need hreflang
• If your "translated" pages are just minor copy variations on the same content, consider if they need to exist at all
• If your content strategy targets one global audience in English, keep it simple