JavaScript is among the most-used programming languages as it can create client-side and server-side applications.

JavaScript has many frameworks and libraries that simplify the creation of web apps and extend their functionality.

Svelte and React are both front-end frameworks that are popular among developers. Which one should you pick as a developer? This article will introduce the Svelte vs. React debate, discuss their differences and illustrate where to use each. 

What is Svelte?

Svelte is an open-source JavaScript online compiler. Unlike most JavaScript frameworks that do most of their work in browsers, Svelte uses its compiler to optimize its code during build time. 

Svelte was created by Rich Harris in 2016 and has since attracted a big user base. According to a Stack Overflow 2022 survey, Svelte is among the most-loved JavaScript frameworks. 

To create a Svelte, you must first have Node.js installed on your local machine. 

After installing NodeJS, you can start with Svelte using these commands:

npx degit sveltejs/template moz-todo-svelte

cd moz-todo-svelte

npm install

npm run dev

This is what will be rendered on your browser

Features of Svelte

• Reactive. Svelte updates DOM at build-time. Developers don’t have to use external state management libraries when using this framework. 
• Uses plain JavaScript. Developers conversant with HTML, CSS, and plain JavaScript will easily learn Svelte. 
• Lightweight and use less code. You can create a simple hello world in Svelte using these few lines of code: 

  let name = "World"



Hello {name}!

Benefits of using Svelte

• Small size: Compared to other frameworks, Svelte’s app is small and loads quickly. 
• Simple syntax: Svelte is easy to learn due to its straightforward syntax. 
• Does not use virtual DOM: Svelte, unlike most frameworks, lacks a virtual DOM, which leads to fast rendering. 
• Great performance: This online compiler compiles code at build time, creating fast and small apps.

What is React?

React is a popular JavaScript library for creating user interfaces. This open-source library is maintained by Meta (formerly Facebook) and powers the user interfaces of popular web apps such as Airbnb, Facebook, and Instagram. 

The first company to use React was Facebook on its newsfeed. When the library was made open-source in 2013, more companies picked it up, and it has become one of the most-used JavaScript libraries in the modern development space. 

React also runs on NodeJS. Once you have Node on your PC, run these commands to set up your React app:

npx create-react-app my-app

cd my-app

npm start

This is the file structure of a React app

Features of React

• JavaScript Syntax Extension (JSX): JSX allows developers to write HTML code in the same file that contains JavaScript code. JSX is also different from HMTL in how it names its divisions (DIVs) as it uses ‘className’ (camelCase) instead of class.
• Virtual Document Object Model (VDOM): React has a lightweight representation of real DOM through its Virtual DOM. When an object’s state changes, the VDOM updates only that object in the real DOM instead of updating the entire project. 
• Modular architecture: React allows developers to write small and reusable components. Updating and maintaining such components is also easy. 

Benefits of using React

• Component-based: React allows developers to split their code into small reusable components. 
• Supports various libraries: You can extend the functionality of a React app using various libraries and frameworks to support functions such as authentication. 
• Declarative: Creating interactive user interfaces is so simple when using React. The declarative views of a React app make it simple to read and debug code. 
• Flexible: You can use React to make various web applications, from social media and entertainment platforms to educational sites. 

Svelte vs. React: Similarities

Even though Svelte and React are different, they share some similarities:

• Component-based. Both Svelte and React follow a component-based architecture. This approach allows developers to split their codebase into small bits. 
• Reactive. Both frameworks eradicate manual intervention as their apps update automatically when data changes. 

Svelte vs. React: Differences 

#1. Size

Svelte’s .gzip version is only 1.6 kilobytes. You can thus load this app fast and are assured of high performance. 

React’s .gzip version is 42.2 kilobytes. The app is slightly bigger as it comes with ReactDOM. 

#2. Performance

React uses a virtual DOM, a temporary memory storage for changes made to the user interface. React is thus faster than Traditional Document Object Model (DOM) used in vanilla JavaScript as Virtual DOM delays updates until rendering and updating can be done effectively.

Svelte does not use the Virtual DOM. This framework interprets its code during build time. Svelte is a serverless-first framework whose DOM is updated whenever an assignment/ action triggers a change in the component stage. 

The absence of the Virtual DOM in Svelte makes a Svelte app faster than React. 

#3. Maintenance

Svelte is less than a decade old, as it was introduced in 2016. However, this online compiler has an amazing development and maintenance team. 

React is maintained by Meta, various companies, and individual developers. This library has a dedicated team, explaining why it always introduces new features. 

React wins when it comes to maintenance. 

#4. Testing

Svelte uses @testing-library/svelte as its testing framework. The library is designed to test applications using an approach that closely mirrors how users interact with the app. 

React uses React Testing Library that tests the components from a user’s perspective. You can also use the Enzyme library if you want granular control over the testing process. 

Svelte and React have dedicated testing libraries to help developers build functional apps. You can also use external testing frameworks like Mocha to test both Svelte and React apps. 

Svelte is a fairly new framework, and its community is not that large compared to React. The number of developers and companies using Svelte is also low. 

React has great community support that creates tutorials, guides, updates, and components. It is among the most-used JavaScript libraries and is maintained by Meta, a tech giant. Getting help from the React community is easy as it is huge and supportive. 

React wins on community support. React developers are also in high demand compared to Svelte. 

#6. Libraries

Svelte has an open-source community that offers extra functionalities to React. For example, you can route your Svelte app using the SvelteNavigator. Svelte also has powerful UI libraries such as Sveltestrap and Svelte Material UI.

React is supported by its open-source community that creates tools and libraries to boost its functionality. For instance, this library has Material UI and React Bootstrap, UI libraries, and also uses React Router for routing. React uses Next.js and Gatsby for server-side rendering. 

Even though Svelte’s community is working hard to add new tools, frameworks, and libraries, React is still far ahead. 

#7. Syntax and ease of use 

Svelte has simple syntax, using pure HTML, JavaScript, and CSS. Anyone with basic knowledge of HTML, CSS and JavaScript will thus master Svelte easily.

React has a steep learning curve as users have to learn and master new concepts such as JSX and CSS-in-JS. When naming classes in a div, React uses className (camelCase), which can confuse someone coming from HTML and CSS. 

Svelte beats React on syntax simplicity as it is easier to learn for those who understand vanilla CSS, HTML, and CSS. 

Which is the best? Svelte or React?

Svelte and React are amazing JavaScript libraries that can create a wide range of applications. Both of them have their strong areas and weaknesses, and deciding on which to use can be challenging. Based on the analysis of features and performance, you can use these frameworks as follows:

When to use Svelte?

• Building small projects: Svelte is suitable if you want to create a simple web, like a portfolio website with a few features. 
• You value performance and optimized code: Svelte doesn’t use Virtual DOM, which makes it faster than React apps. 
• You want to build dynamic user interfaces: This compiler compiles code into highly optimized JavaScript, making it ideal for user interfaces that change a lot. 

When to use React?

• When building complex user interfaces: The reusable components feature of React makes it a perfect option if you want to build apps that have complex interfaces. 
• When building large apps.:React has loads of features that make it easy to build large applications. 
• When looking for a library with many libraries, tools, and great support: React is supported by a large community, and you are thus likely to get help fast.

Conclusion

We now hope you can engage in the Svelte vs. React debate and state their similarities, differences, and the best use case. Always ensure you determine the nature of the app you want to create to make an informed decision.

Svelte is suitable if you value speed when creating small applications and building dynamic interfaces. On the other hand, React should be your go-to library if you want to build complex user interfaces, want a library with great support, and when building large apps. 

You may also explore the differences between React and React Native.