Fix Next.js i18n SEO issue with localePrefix never (no URL prefixes)

Problem: Next.js 16 + next-intl with localePrefix: 'never' (clean URLs without /de /en). Google Search Console shows 'Crawled - currently not indexed' and 5xx errors. All languages share same URL.

Google requires unique URLs per language for proper indexing.

Fix - Use locale prefixes:

// next-intl config
export default {
  localePrefix: 'as-needed', // or 'always'
  defaultLocale: 'en'
}

This gives /pricing (English default) and /de/pricing, /es/pricing.

Why it fails:

• Googlebot doesn't send cookies → sees only default language
• Same URL for multiple languages = duplicate content
• AWS Amplify officially supports Next.js up to v15, not v16 (causes 5xx)

Alternative:

• Use subdomains: de.site.com, es.site.com
• Use separate domains

Both allow proper hreflang tags and indexing.

Source: https://www.reddit.com/r/nextjs/comments/1qxfo79/