React Strict DOM: Writing Once for Web & Native

At Twitter, Gallagher saw component styles change unpredictably when surrounding containers affected their contents. React Native’s styling and composition offered a way to make components more controlled, so he began exploring that approach for the web. The early goal was web development, though the team also tried bringing web app features to native.

Gallagher says React Strict DOM has continued to gain features and use within Meta, though he does not call it stable. React Native’s New Architecture, synchronous APIs, DOM APIs, Intersection Observer, and newer CSS capabilities make it more practical to reproduce web experiences on native.

Gallagher describes Meta’s adoption as early and says he cannot discuss products that have not been made public. React Strict DOM syntax is transformed by a Babel plugin into ordinary web elements such as `div`, while its styling is compiled into static CSS. This lets teams use the syntax on the web and keep the option of running the code on native.

Gallagher says the styling approach provides encapsulation and portability, including reuse of design system components between Facebook and Instagram. He envisions developers using React Strict DOM instead of React DOM plus a styling library, with native support available as an option. Component libraries could share most of their code and use platform-specific implementations for features such as virtualized lists.

Gallagher names Zalando as an early adopter but does not identify other companies experimenting with the project. He points to momentum in React Native toward closer alignment with the web, including interest from Expo and Callstack. Familiar web APIs could help developers build native apps while tooling handles much of the complexity of shipping them.