Internationalization (i18n)

Nextra’s App Router i18n uses locale-prefixed routes, such as /en and /ja, backed by a content/<locale>/ directory convention and a [lang] dynamic route segment that resolves each locale’s pages independently. A proxy.ts file re-exports proxy from nextra/locales, which inspects the incoming request and redirects visitors to their preferred locale when they hit an unprefixed path. A <LocaleSwitch> component rendered in the navbar lets visitors change locales manually at any time, independent of that automatic detection.

This very site demonstrates full parity: every page that exists in English also exists in Japanese, and vice versa, because incomplete i18n coverage would otherwise leave broken links or 404s behind whenever a visitor switches locales mid-navigation. This was an issue found and fixed during this project’s development, which is why per-locale content coverage is treated as something to check explicitly rather than assume. English (en) is this site’s default locale (defaultLocale), configured in next.config.mjs.