Internationalization and Localization for Global Apps

Global apps reach users across many languages and cultures. Internationalization, or i18n, prepares the software so text, dates, and numbers can be adapted. Localization, or l10n, applies those adaptations for a specific locale. Together they help a product feel native, not foreign. Start early and keep content separate from code; this saves time later and avoids patchy changes.

Key areas to plan

  • Text and content should live in translation files, not in the UI code.
  • Use locale codes like en, en-US, fr-FR and follow IETF language tags.
  • Dates, times, and numbers must format for the user’s locale.
  • Support both left-to-right and right-to-left scripts.
  • Fonts and icons need broad script coverage.
  • Images, colors, and cultural cues should be considered.

Implementation steps

  • Inventory all user-facing strings.
  • Create per-language translation files in an i18n folder.
  • Apply locale-aware formatting for dates, times, and numbers.
  • Add a language switcher and a sensible fallback language.
  • QA with native speakers and automated checks for consistency.

Hugo and PaperMod tips

  • Hugo i18n stores translations in the i18n folder, typically as YAML or TOML.
  • Reference strings in templates using the i18n function.
  • Keep a clear default language and explicit fallbacks.
  • Use PaperMod’s language switcher and ensure menus and labels are translated.

Common pitfalls

  • Missing translations or placeholders left in the UI.
  • Text embedded in images or hard-coded strings.
  • Ignoring right-to-left layouts or not testing fonts.
  • Failing to test on real devices and on different browsers.

Testing tips

  • Work with native speakers to verify phrasing and tone.
  • Test on multiple devices, screen sizes, and locales.
  • Check plural rules with different counts and genders.
  • Verify date and time formats across time zones.

Key Takeaways

  • Plan internationalization early and separate content from code.
  • Use proper locale codes, fallbacks, and locale-aware formatting.
  • Test with real users to ensure clarity and cultural fit.