404s and Hreflang Errors on Multilingual Sites

Multilingual sites have more ways to create 404s than single-language sites. Each language version has its own URLs, translations are often published at different times, and language switchers assume an equivalent page always exists.

Where multilingual 404s come from

Missing translations. An article exists in Turkish but not in English. The language switcher still builds /en/blog/... and sends visitors to a 404.

Different slugs per language. If the switcher simply swaps the language prefix (/tr/ → /en/) while slugs are translated, every switch on a translated page breaks.

Partially deleted content. A product is removed in one language but stays in another, leaving hreflang tags pointing to a dead URL.

Migrations. Moving from subdomains (en.example.com) to folders (/en/) without mapping all language versions.

Hreflang tags pointing to 404s

Hreflang tells search engines which page is the equivalent in another language. For it to work:

• each language version must list all alternatives, including itself,
• the references must be reciprocal (A points to B, and B points back to A),
• every target must return 200 and be indexable.

If a hreflang target returns 404, redirects or is noindexed, search engines may ignore that pair. The result: the wrong language version may appear in search results for some users.

How to fix the language switcher

• Link each page to its actual translated URL, not to a URL built by swapping the language prefix.
• If no translation exists, either hide that language in the switcher or link to the closest relevant page in that language (such as the blog index), and say so clearly.
• Don't send visitors to the other language's homepage without explanation.

Redirect rules for removed translations

When a translation is removed:

• redirect it to the closest equivalent in the same language,
• if none exists, a 404 is acceptable, but remove it from hreflang tags and the sitemap,
• avoid redirecting to a page in a different language; users don't expect it and it confuses hreflang signals.

Be careful with automatic language redirects

Redirecting visitors by IP location or browser language can prevent search engines and users from reaching some versions. Search engine crawlers often come from a single country. Prefer suggesting a language with a banner instead of forcing a redirect, and use x-default for the fallback version.

How to audit

1. Crawl the site and extract hreflang targets; check their status codes.
2. Compare URL counts per language to spot missing translations.
3. Review 404 logs by language folder; a spike in /en/ 404s often points to a broken switcher.
4. Check Search Console for 404s in each language section.

For the general process, see How to Find and Prioritize Broken Links and use WebAudit Inspector before launching new languages.

Summary

Multilingual 404s usually come from missing translations, prefix-swapping language switchers and hreflang tags pointing to removed pages. Link to real translated URLs, redirect within the same language, keep hreflang targets live and avoid forced geo-redirects. no404 shows 404 hits per URL in real time, making language-specific spikes easy to catch.