iOS Localization & Internationalization

Localize Apple-platform applications using String Catalogs (.xcstrings), compiler-generated symbols, locale-aware FormatStyle, and right-to-left (RTL) layout adaptation. Targets Swift 6.3 / iOS 26+.

Contents

• String Catalogs (.xcstrings)
• String Types: Key vs Resource
• Pluralization & Variations
• FormatStyle & Locales
• Right-to-Left (RTL) Layout
• Common Mistakes
• Review Checklist
• References

String Catalogs (.xcstrings)

String Catalogs are the standard format for Xcode localization. Xcode automatically extracts localizable strings from source code on every build: