Language Detection
Automatically determining the user's preferred language for localization.
Definition
Language detection is the process of automatically determining which language to display to a user. Modern applications use multiple signals: Accept-Language HTTP header, URL path/subdomain, user preferences in account settings, browser/OS language settings, IP geolocation, and cookies. The detection order and fallback logic significantly impact user experience.
Examples
- →Accept-Language header: 'es-MX,es;q=0.9,en;q=0.8'
- →URL-based: example.com/es/ or es.example.com
- →Geolocation fallback: IP in Germany → suggest German
- →User preference override: saved in account settings
Frequently Asked Questions
What's the best language detection strategy?
Priority order: 1) User's explicit preference (account/cookie) 2) URL path/subdomain 3) Accept-Language header 4) Geolocation (optional, less reliable) 5) Fallback language. Always allow manual override.
Should I auto-redirect based on language detection?
Debated. For SEO: URL-based locales are better. For UX: show detected language but let users switch easily. Never force redirects without escape—some users access foreign versions intentionally. Google recommends against geo-redirect.