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Mobile Localization Infrastructure

1 post · May 2022

What this trail covers

Meta has developed a custom mobile localization infrastructure featuring downloadable language packs for Android and iOS. This system, built around the FBT framework, addresses challenges in translation accuracy (supporting gendered text and plurals) and app size by enabling on-demand download of language packs. This infrastructure has been adopted by Facebook and Workplace, reducing IPA size and improving the delivery of localized experiences.

All Meta trails
  1. Language packs: Meta’s mobile localization solutionThis post details the development of a custom mobile localization infrastructure at Meta, including the creation of downloadable language packs and the FBT (Facebook Translation) framework. It explains the limitations of native platform localization, the design of the FBT API for handling complex translations (gender, plurals), the end-to-end flow of language pack construction and delivery, and the structure of language pack files. Improvements to localization setup for users with poor network access are also discussed. The infrastructure has reduced the Facebook iOS app size by 16.6 MB.