x-default

The x-default value is optional but useful whenever your hreflang set does not cover every language or region a visitor might use. Google introduced it in 2013 for homepages and landing pages that auto-detect location and redirect, giving crawlers an explicit fallback instead of leaving Google to pick one for you.

How to implement it

Add one more <link> tag to your existing hreflang annotations and point its href at the page unmatched users should land on, typically a language selector or a generic global homepage.

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

A few rules that keep it working:

• Every URL in the cluster references the same annotations, and links must be bidirectional (each page lists all variants, including itself).
• Google designed x-default for language selector pages, so it works best there, but any page can carry it.
• The same URL can legitimately serve as both a language version and the x-default. Many global sites point x-default at their English or US page, so that one URL gets both an en-us tag and an x-default tag. Just make sure the fallback is genuinely the right page for unmatched users.

You can deliver these annotations in HTML <link> tags, HTTP headers, or an XML sitemap. Pick one method and keep it consistent across the site.