Internationalization bugs are the bugs that only appear when your product goes global. Text that overflows in German (30% longer than English). Date formats that confuse American and European users. Currency symbols that break the layout. Right-to-left languages that mirror the entire UI incorrectly.
AI coding tools generate English-centric code by default. They hardcode date formats, assume left-to-right layout, and generate UI with English string lengths in mind. When the product localizes, these assumptions break silently.
Common i18n Bugs AI Code Introduces
Hardcoded strings instead of translation keys
Date/time formatting without locale awareness
Number formatting (1,000 vs 1.000) not localized
Text overflow when translated strings are longer
Currency display hardcoded to $ instead of locale-appropriate symbol
RTL layout not mirrored for Arabic/Hebrew
String concatenation that breaks in languages with different word order
Testing i18n Systematically
TestSprite tests your application's rendering and behavior across locales. When the agent navigates your app, it can verify that text fits within containers, dates display correctly, and interactive elements work regardless of locale settings.
For teams expanding internationally, i18n testing on every PR catches localization bugs before they reach users in new markets.