Localization

Discipline-enforcing skill for app localization and internationalization. String Catalogs are the unified format for everything (replacing legacy .strings and .stringsdict); SwiftUI and UIKit have first-class localization APIs; Xcode 26 adds compile-time-safe generated symbols.

When to Use

Use this skill when:

• Setting up String Catalogs in Xcode 15+
• Localizing SwiftUI or UIKit views and strings
• Handling plural forms across languages (critical for Slavic, Arabic, Hebrew, etc.)
• Supporting RTL languages (Arabic, Hebrew) and verifying layouts
• Formatting dates, numbers, and currencies by locale
• Migrating from legacy .strings / .stringsdict to String Catalogs
• Preparing App Shortcuts and App Intents for localization
• Debugging missing translations, wrong plural forms, or layout mirroring problems
• Adopting Xcode 26 type-safe generated symbols and the #bundle macro
• Writing a script or tool that reads or edits an .xcstrings file

Example Prompts

• "How do I create and use a String Catalog?"
• "How do I handle pluralization correctly for Polish or Arabic?"
• "How do I support RTL layouts in SwiftUI without re-doing every leading/trailing?"
• "How do I use Xcode 26's type-safe localization symbols?"
• "How do I migrate from .strings to a String Catalog?"
• "When should I use LocalizedStringResource instead of String(localized:)?"
• "How do I localize an App Shortcut phrase?"
• "My script rewrote the whole String Catalog — what layout does Xcode expect?"
• "Two different features both show 'High' — why do they share one translation?"

What This Skill Provides

• String Catalog discipline – .xcstrings is the single source of truth; automatic key extraction; per-language plural and device variations; translation-state tracking
• SwiftUI patterns – Text("…") localizes automatically, String(localized:comment:) with translator-facing comments, LocalizedStringResource for deferred resolution at render time, LocalizedStringKey for view APIs
• UIKit patterns – modern String(localized:) API (iOS 15+), bundle-specific lookup, NSLocalizedString for older deployment targets
• Pluralization rules – use String Catalog plural variations rather than format-string tricks; language plural rule categories (zero/one/two/few/many/other); how Polish, Russian, and Arabic disagree with English
• Device and width variations – strings per device class, and numeric-width variants (not size classes or Dynamic Type)
• RTL discipline – leading/trailing instead of left/right, layout mirroring, image flipping for directional symbols, testing with the RTL Pseudolanguage scheme option
• Locale-aware formatting – Date.FormatStyle, IntegerFormatStyle, Decimal.FormatStyle.Currency, Measurement for units; avoid baking culture-specific patterns into strings
• App Shortcuts localization – phrases, parameter prompts, response dialogs, all routed through String Catalogs
• Xcode 26 generated symbols – compile-time type safety for keys (Text(.appHomeScreenTitle)), automatic comment generation, #bundle macro for Swift Package localization, refactoring tools
• Migration paths – .strings → .xcstrings, .stringsdict → catalog plural variations, removing manual Localizable.strings from build phases
• Writing a catalog from a tool – the byte layout Xcode expects, the two key styles a reader must handle, xcstringstool extract/sync (including what sync prunes), and why one English word used for two meanings ships one translation

Related

• hig – typography and RTL layout guidance
• typography-ref – font system that must adapt to per-locale Dynamic Type sizing