React JS is a flexible library focused on building user interfaces using JavaScript and JSX, while Ember.js is a full-featured, opinionated framework for building ambitious web applications, following a set of strong conventions and best practices.
| Feature | React JS | Ember JS |
|---|---|---|
| Type | Library for building user interfaces | Full-featured framework for building web applications |
| Author & Community | Developed and maintained by Facebook | Developed by Yehuda Katz and the open-source community |
| Learning Curve | Moderate, mainly due to JSX syntax | Steeper, due to strong conventions and best practices |
| Language | JavaScript (optionally, TypeScript) with JSX | JavaScript (optionally, TypeScript) |
| Architecture | Component-based, focuses on the view layer | Component-based, with a strong focus on conventions |
| Data Binding | One-way data binding | One-way data binding with actions |
| Performance | Virtual DOM for optimized rendering | Uses Glimmer rendering engine for optimized rendering |
| State Management | External libraries (e.g., Redux, MobX) | Built-in state management with Ember Data |
| Ecosystem | Large ecosystem with numerous libraries and tools | Smaller ecosystem, but with a focus on stability |
| CLI & Tooling | Create React App for scaffolding, React DevTools | Ember CLI for scaffolding, Ember Inspector |
React JS is a popular and flexible library for building user interfaces with a large ecosystem, while Ember.js is a full-featured, opinionated framework for building ambitious web applications, following a set of strong conventions and best practices. The choice between the two depends on factors such as project requirements, team familiarity, and personal preferences.