Category: Case Study | Format: Session

12:00 pm - 12:40 pm | Room B

Building Beyond Locale: Custom Internationalization for Global Learning at Oppia Android

Session Description:

Internationalization and localization are notoriously complex, especially for educational platforms where content needs to be understandable, accessible, and culturally relevant. In this talk, I’ll share how the Oppia Android team built a custom locale system to deliver interactive lessons to learners in their preferred languages, even those not officially supported by Android's default Locale class. Our motivation stemmed from a core product goal: making quality education accessible globally. Oppia's lessons are translated by humans, both text and audio, then integrated into the app. But to present this content reliably and contextually across diverse languages that may not be natively supported by Android like Hinglish and Naija, we needed a flexible, extensible locale system. So we engineered our own solution: a custom locale framework layered on top of Java’s Locale, tailored to our translation pipeline, content model, and UI rendering. This system has allowed us to reach underserved communities in over 20 countries including Kenya, Tanzania, India, Nigeria, Brazil, and Egypt, with more than 100k installs globally while still in Beta. In user studies, learners using Oppia in their preferred languages reported stronger concept mastery compared to those relying solely on traditional textbooks.