React is a popular JavaScript library for building user interfaces, developed by Facebook. It allows developers to create interactive and dynamic UI components using a declarative approach. React's virtual DOM implementation ensures efficient rendering performance by minimizing actual DOM manipulations. It also promotes component reusability and composability, making it easier to manage complex UI structures.
Svelte is a modern JavaScript framework that compiles your code to highly efficient vanilla JavaScript at build time. It focuses on writing declarative code that updates the DOM directly, resulting in minimal overhead and faster performance. Svelte's reactive declarations and reactive assignments simplify state management and make building interactive web applications intuitive and straightforward.
React is currently one of the most popular and widely used JavaScript libraries for building user interfaces. It has a large and active community, extensive ecosystem, and is frequently used in production by many companies. Svelte, although gaining popularity, is not as widely adopted as React.
Size
React is a larger library compared to Svelte. React includes a Virtual DOM implementation and additional features like routing and state management need to be added through separate packages. Svelte, on the other hand, is smaller in size and offers a more bundled approach where the compiler generates highly efficient and optimized code.
Performance
Svelte is known for its excellent performance. It compiles components at build-time, resulting in highly optimized and efficient JavaScript code. React, with its Virtual DOM, requires additional reconciliation steps during runtime, which may impact performance in complex applications. However, React still has good performance and optimization techniques like memoization and lazy loading.
Developer Experience
React has a mature and well-supported ecosystem with a plethora of tools, libraries, and resources available. It has a large community that provides extensive documentation, tutorials, and a rich set of third-party libraries. Svelte, although growing, has a smaller ecosystem with relatively fewer resources available. However, Svelte offers a simpler and more intuitive development experience due to its reactive approach and compiler-driven nature.
Learning Curve
React has a steeper learning curve compared to Svelte, especially for beginners. React has a larger API surface area, complex lifecycle methods, and requires understanding concepts like state management and JSX. Svelte, on the other hand, has a smaller and more straightforward API, and its reactive programming model makes it easier to grasp for newcomers.
Component Model
Both React and Svelte provide a component-based approach to building user interfaces. React uses a Virtual DOM and props/state-based approach, which allows for better reusability and composition. Svelte, on the other hand, leverages its compiler to generate highly optimized components with reactive properties and event handling, resulting in a smaller footprint and potentially better performance.