An Introduction to Svelte and Its Advantages over React

Convincely / / An Introduction to Svelte and Its Advantages over React

Svelte is an open-source front-end development tool used for creating interactive web pages. It was initially released in November 2016 by Richard Harris. Since then, Svelte has gained immense popularity, and many developers have fallen in love with its unique way of building apps.

The general purpose behind Svelte is similar to other existing Javascript frameworks like React and Vue in that it enables developers to build web apps. However, Svelte is not just another Javascript framework or library, as most people believe. It is a modern Javascript compiler intended to generate optimized Javascript code without any runtime overhead.

The approach provided by Svelte for building web applications is different from other frameworks such as React and VueJS. React, and Vue performs most of their work in the user’s browser, While Svelte transfers that work into a compile step, which only occurs when you build the app, producing well-optimized Vanilla Javascript. So, only that VanillaJS directly manipulates the DOM and finally makes it to the browser. Because of this reason, Svelte is also called a “Disappearing Framework.”

The outcome of this approach by Svelte is not only limited to smaller application bundles and improved performance of the application, but also a more friendly developing experience for people with less experience with the modern tooling ecosystem.

Svelte and React both offer a similar component-based architecture, which facilitates bottom-up development and enables the sharing of their components between apps. The major difference between them is that Svelte is a compiler that converts your app into pure JavaScript during build time in contrast to React, which interprets the application code during run time using a virtual DOM.

Svelte stays close to the standard web development model with HTML, CSS, and JS by simply adding some extensions to HTML and JavaScript. It has also got a small number of tools and concepts to learn when compared with other frameworks.

Some well-known use cases of Svelte are single-page applications, Interactive visualization apps (Ex: Apps that provide data visualization through video), and web apps for restricted internet connection and low-intensity devices. Even though Svelte is relatively young, some popular apps are built with it, such as TeamSpeak, Houses Of World, Doka by PQINA, and Tableplop.

Advantages of Svelte over React

Now, you have a good understanding of Svelte. Let’s see what advantages Svelte has over React.

1. Automatic updates

Svelte enables automatic updates of data to your interface through the declared variables. This eliminates the need to wait for the virtual structure to reflect changes, thereby ensuring a faster pace and enhanced user experience.

2. Reduced code

Svelte uses far less code than React. Because of Svelte’s reactive nature, developers can write more concise code, which ultimately reduces the development timeline and cost. It also allows developers to implement the real business logic without getting stuck with code complexities.

3. Faster building times

The building time of Svelte apps is extremely fast when compared to React or other frameworks. The use of the rollup plugin as the bundler and Svelte surgically updating only the parts of the DOM that change leads to these faster execution times.

4. Smaller bundle size

When a Svelte app is compiled, the bundle size is much smaller than React, which is a huge upside of the Svelte. It results in a lower initial load time and a reduced duration to render the UI.

5. No virtual structure / DOM

Like React, Svelte does not use the concept of virtual DOM. Instead, it operates directly with the real DOM and moves the work into the compile step when you build the production application.

Svelte has greatly improved its performance by eliminating the use of Virtual DOM. It avoids adding any library package code during run time and compiles the code into tiny VanillaJS code, which guarantees to be brilliantly optimized and fast. The build size is also very small, performant than React.

6. Highly lightweight tool

Svelte is an extremely lightweight and compact tool compared to React. It uses modern Javascript to provide clean as well as thoroughly user-focused interfaces for web apps. Moreover, it can shrink its size to 4.1KB.

7. Readable and straightforward

Svelte produces high quality, readable as well as compact code. This enables faster development and easy maintenance for web apps. Svelte also offers a more straightforward store implementation than React’s context API.

8. Easy to learn and get started

The learning curve of Svelte is very low compared to React and other frameworks due to its clean and simple code. A significant part of Svelte codebase consists of plain HTML, CSS, and Javascript. There’s no need for additional knowledge of typescript or JSX, and anyone with basic Javascript knowledge can easily get started with a Svelte project.

9. Easy binding of classes and variables

Binding classes and variables are comparatively easy with Svelte, and custom logic is not required when binding classes.

10. Encapsulated styles

Unlike in React, styles in Svelte components are encapsulated, which allows flexible styling. Furthermore, Svelte also has a built-in mechanism to identify unused CSS selectors and help developers remove those unnecessary codes. It also provides built-in directives for transitions as CSS animations are run outside the main thread. All these things in Svelte have a good impact on the performance of the app.

11. No need for external libraries

Being a UI framework, React requires the use of more external libraries in the development environment to perform various tasks, whereas Svelte comes loaded with its own internal store APIs. Due to this, there is no need to install any external library for Svelte to perform any task.

12. Perfect for smaller projects

The Svelte compiler has lower dependencies and boilerplates. Thus, the size of an application built using Svelte is much smaller than an app developed using React. This makes it an ideal choice for small app projects like simple e-commerce applications.


Javascript libraries, frameworks, and tools are evolving day by day. With Svelte recently entering the market, it has indeed given good competition to traditional Javascript frameworks and enabled developers to build powerful, fast, and lightweight apps with less code. It also shows some noticeable improvements in certain features when compared to React and other frontend frameworks.  Despite Svelte being quite new on the field and still has some catching up to do, it promises simplicity as well as speed for a better user and developer experience.

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