Hreflang x-default and invalid codes by platform
| Platform | Homepages with hreflang | No x-default | Invalid code |
|---|---|---|---|
| Shopify | 1,398 | 6.6% | 2.4% |
| WordPress | 952 | 45.9% | 1.2% |
| Wix | 66 | 0.0% | 0.0% |
| Other or custom | 3,156 | 40.9% | 2.9% |
| All | 5,584 | 32.6% | 2.5% |
Source: PageSpeed Matters, Oct 2026. Invalid codes accept UN M.49 regions such as es-419; a strict ISO check gives 3.4% overall.
Summary
Hreflang tags tell Google which language or regional version of a page to show to which searcher. The x-default value covers everyone else: the page to show when no listed language or region matches. Google recommends it, and without it, searchers outside your listed markets get whichever version Google picks.
We checked the homepages of sites that rank in Google's top 20 for US searches. Among 5,584 ranking sites with hreflang on the homepage, 32.6% have no x-default tag, about one in three. Platform is the biggest divider: Shopify stores almost always include it, while WordPress and custom sites often do not.
What we measured
We started from the domains ranking in Google's top 20 for 10,019 US searches, and kept the 5,584 sites with hreflang on the homepage. We read each homepage's hreflang links and validated every code against ISO 639-1 language codes and ISO 3166-1 region codes. The data was collected in October 2026.
Two limits apply. We looked at homepages only, and read up to 30 hreflang tags per page, so this is not a full site audit. For invalid codes, we accept UN M.49 regions such as es-419 (Spanish for Latin America) as valid. Under that definition, 2.5% of sites use at least one invalid code. A strict ISO check that rejects those regions gives 3.4%.
A third of hreflang sites skip x-default
Of 5,584 ranking sites that use hreflang on the homepage, 32.6% have no x-default tag. These sites have already done the work of listing their language versions, but have not said which page to show everyone else.
Skipping x-default is not an error in Google's eyes, since the value is optional. But it leaves the choice to Google for any searcher whose language or region is not on the list, and the fewer markets a site lists, the more searchers that covers.
32.6%
Share of the 5,584 ranking sites with hreflang on the homepage that have no x-default tag.
Platform is the biggest divider
Which platform a site runs on predicts x-default use better than anything else in the data. Only 6.6% of 1,398 Shopify homepages with hreflang skip x-default. On WordPress the figure is 45.9% of 952 homepages, and on custom or other platforms it is 40.9% of 3,156. None of the 66 Wix homepages with hreflang skipped it.
The likely reason is who writes the tags. Shopify generates hreflang tags for its language and market setup itself, so stores get a consistent set by default. WordPress sites usually depend on a translation or SEO plugin and its settings, and custom sites depend on whoever wrote the templates.
Service sites and small setups skip x-default most
Local and professional service sites skip x-default most often: 46.8% of 971 have none. Publishers and how-to sites follow at 37.8%. Online store and product sites (26.2% of 2,318) and software and marketing sites (26.6% of 964) are the most likely to include it, which likely reflects the Shopify pattern above for stores.
Setup size matters too. 38.6% of 2,257 sites with only two language codes skip x-default, against 22.9% of 1,188 sites with 6 to 15 codes. A site with two languages may feel it does not need a fallback, but searchers outside both markets still need a default page.
Invalid codes are rare but grow with scale
2.5% of the 5,584 sites (138) use at least one invalid hreflang code. The usual mistakes are an unknown language, a region that is not a country, such as en-EU, or en-UK where the correct code is en-GB, and underscores in place of hyphens.
The more codes a site lists, the more likely one is wrong. 8.1% of 1,049 sites listing 16 or more language codes have at least one invalid code, against 0.4% of 2,257 sites with two codes. Long lists are often maintained by hand or built from internal locale names, which is where codes like en_US or en-UK creep in.
What this means for your site
If your site uses hreflang, check three things on every page that carries it:
- There is an x-default entry, pointing to your global page or a language picker.
- Every code is a valid ISO 639-1 language, optionally followed by a hyphen and an ISO 3166-1 country, such as en-GB. Google's documentation asks for ISO 3166-1 Alpha 2 region codes, so a strict check may also flag regions like es-419.
- The set is the same on every language version, with each version listing itself and all the others.
On WordPress, check the hreflang settings in your translation or SEO plugin, since x-default is often a separate option. On a custom build, generate the tags from one list of locales rather than writing them by hand, so codes stay valid as you add markets.
Sources
- PageSpeed Matters analysis of Google top 20 results for 10,019 US searches, October 2026
- Google Search Central, localized versions of your pages: https://developers.google.com/search/docs/specialty/international/localized-versions
Frequently asked questions
What is hreflang x-default?
It is the hreflang value that names the page to show when no listed language or region matches the searcher. Google recommends it, usually pointing to a global page or a language picker.
How many sites are missing x-default?
Among 5,584 sites ranking in Google's top 20 for US searches with hreflang on the homepage, 32.6% have no x-default tag. The rate is 6.6% on Shopify, 45.9% on WordPress and 40.9% on custom or other platforms.
How common are invalid hreflang codes?
2.5% of those 5,584 sites (138) use at least one invalid code, such as en-UK instead of en-GB, a non-country region like en-EU, or underscores. The rate rises to 8.1% of sites listing 16 or more codes.
Adding x-default and cleaning up hreflang codes is a one-time template change that gives Google a clear page for every searcher. Need help with this? See our technical SEO services.