Svelte vs React: Which framework is better ?
While React is a very broad solution that offers developer a lot of choice, Svelte is focused on build time optimizations to you web frontend.
Whether or not Svelte is the right choice for you depends on many factors and this article will cover this topic in great depth.
The following table offers a good comparative differences between React and Svelte. We discuss some of these in detail.
|Reactive||all variables are reactive||You have to decide which variables should be reactive|
|Bundle size||Highly optimized||Optimizations are possible|
|Performance||Extremely Good||Can be pretty good|
|Community Support||Increasing but less||Huge|
Svelte follows the principle of putting as much work as it can into the build process. Which means it generates pure HTML/JS/CSS code that renders into your browser without any fancy techniques like Virtual DOM. React on other hand is a runtime framework. It executes a lot of code in your browser.
Conside the following Svelte code.
If you are familiar with React you will notice that the variable count is not defined in any special way and is still being treated as reactive. If the count changes anywhere, the count will update autmatically in UI.
In react this is not possible. In react you will have to use useState hook to define a special variable for reactivity and use a special setter method to change the variable value.
Svelte makes this possible because you can write your code assuming every varible is reactive and during compile time Svelte will figure out which variables are indeed being treated as reactive and convert them into highly optimized browser code. The details of how Svelte would ensure reactivity is hidden from us.
Svelte is smaller in size than React due to its compile time optimizations. React is 44KB gzipped where as Svelte is around 2KB gzipped.
Svlete by default has better performance in browser due to its less memory usage and lack of a virtual dom. Since react uses a virtual dom, it consumes a lot of memory. Secondly reach changes are first applied to the virtual DOM and later to the real DOM, which results into a performance penalty. In case of Svelte no such virtual DOM is used and hence it is much quicker to execute.
Svelte has better performance in the browser by default than React because it uses less memory and does not have a virtual DOM.
React uses a virtual DOM, which is a copy of the real DOM that is used to track changes and updates. This can be a memory hog, especially for large applications.
As a result of these differences, Svelte can be much faster than React, especially for applications with a lot of components or frequent updates.
React is an extremely popular library. It is used by some of the largest websites to ever exist on planet such as Facebook. So it is not be discounted easily against a new framework like Svelte.
React is very mature technology and is used by thousands of large companies serving billions of users every day. The open source community around it is huge and there are plugins, frameworks and in some case entire companies built around React.
Svelte in comparison is much smaller, upcoming and unproven technology. We are yet to see a large scale web application built using Svelte.
React is a highly customizable library, and frameworks like Next.js have shown that it is possible to build highly performant web applications using React.
Next.js is a React framework that includes features like server-side rendering (SSR) and static site generation (SSG). These features can help to improve the performance of React applications by rendering pages on the server or generating them statically, which can reduce the amount of work that needs to be done in the browser.
While Next.js's SSG may not be as powerful as Svelte's, it can still give React a significant performance boost.
In addition to Next.js, there are other React frameworks that can help to improve performance, such as Gatsby and Remix. These frameworks also offer features like SSR and SSG, which can help to make React applications faster.
React has excellent support and well understood patterns to design extremely complex and large applications. For example, libraries like Redux and Jotai for global state management. MUI for UI components, Jest for testing and so on.
Svelte is still young in this regard and has a long way to go before it sees such an ecosystem of large scale applications and design patterns.
As the application sie grows, Svelte's advantage of smaller bundles gives diminishing returns compared to React.
React is a good default choice for most projects, but it is not always the best choice. If performance and bundle size are of paramount importance to your application, then Svelte may be a better option.
Ultimately, the best way to choose between React and Svelte is to consider your specific needs and requirements. If performance and bundle size are critical to your application, then Svelte may be a better choice. However, if you need a framework that is mature and has a large ecosystem of libraries and tools, then React may be a better choice.
I believe that a good engineer should focus on the core principles of engineering, rather than worrying too much about frameworks. Svelte provides some excellent techniques in front-end engineering that every front-end engineer should be familiar with. Even if Svelte does not become widely adopted, its optimizations to reduce the complexity of client-side code may be adopted by other frameworks, such as React.
Yes. You should spend some time learning Svelte.
Svelte is an interesting framework that is increasing in popularity but it is not as mature as React and might not be a default choice for most applications. However, it is worth a developers time to learn this new framework to understand what problems it solves better than React. Chances are that the techniques of Svelte would eventually see adoption in other frameworks.