i18next
Framework-agnostic i18n if you're not on Next.js, or want the same setup across a React Native app and a web app.
What is i18next?
i18next is a JavaScript internationalization framework that isn't tied to any one meta-framework. It handles translation loading, namespacing, pluralization, interpolation, and language detection, with official bindings for React, Vue, Angular, Node, and React Native. It's the older, more battle-tested option in the space, predating most of the Next.js-specific i18n libraries built on top of it.
Key features
- Plugin ecosystem covering backend loading (HTTP, filesystem), browser language detection, and caching
- Works identically across a React web app and a React Native app, which is the main reason teams pick it over a framework-specific library
- Mature pluralization and interpolation rules covering languages with complex plural forms, not just singular/plural
- Large community and long track record, so edge cases in real production apps are usually already documented somewhere
Who it's for
Teams with a multi-platform codebase (web plus React Native, or multiple frontend frameworks) who want one i18n setup instead of a different library per platform. If the whole app is Next.js App Router, a purpose-built library will usually integrate more smoothly with routing and server components.
Pricing
Free and open source. There's no paid tier for the library itself, though the same team sells Locize as a hosted translation management layer on top of it.