An Ultimate Guide on How to Add TypeScript in React App

ReactJS is one of the most trending and greatest front-end libraries, which has become the primary library for many developers working on front-end development projects. TypeScript, on the other hand, refers to a statically typed programming language that makes JavaScript code highly predictable and easy to understand. The key reason why TypeScript is crucial to React native mobile app development is that it helps developers to create new things while designing products on the basis of the customer’s behavior. Let’s discuss an Ultimate Guide on How to Add TypeScript in React App.

Why create a React app using TypeScript?

The react applications will become more predictable using TypeScript to create new high-end mobile apps, thanks to its ability to catch mistakes during the runtime (compilation). Here, we have discussed the steps of creating a simple react application and adding typescript to the ReactJS websites.

What is TypeScript Compiler?

Browsers and Node don’t accept TypeScript directly; they just comprehend JavaScript. Therefore, to transform a file App.tsx, you need to first convert it into a JavaScript or jsx file. As a result, all component files are converted from jsx to tsx, and setupTests.js is renamed as setupTests.ts.

To perform this conversion, developers use the TypeScript compiler where different file extensions can get used because the compiler has to understand while files to compile vs pure JavaScript files.

What is TypeScript?

The typeScript was launched in 2019, and in no time, it got ranked as the 7th most-used language on GitHub. But not every developer is well-known for its potential and scope. So, let us first understand what is TypeScript?

According to the official statement, TypeScript refers to a typed superset of JavaScript that compiles to plain JavaScript. It is also developed and maintained by Microsoft and the open-source community.

“Superset” in TypeScript means that the language contains varied features and functionality of JavaScript. TypeScript also offers developers control over their code base via its type annotation, classes, interface, and sparing developers to manually fix bugs in the entire console. However, TypeScript wasn’t introduced to simply alter JavaScript. Instead, it expands on JavaScript with great features. For instance, any program written in plain JavaScript will also run in TypeScript, including cross-platform mobile apps and back ends in Node.js.

It means that you can write React apps in TypeScript or hire react native developer who can help you to navigate the entire platform with ease.

What are the importance of TypeScript ?

If you are unsure whether or not to choose TypeScript or how to avail its benefits, here are a few advantages you must know:

Fewer bugs

Developers cannot eliminate all the bugs from their code, but they can definitely reduce them. TypeScript analyses the types at compile time and throws errors if there is any variable type change. The ability to find these obvious yet frequent errors early makes it a lot easier for developers to manage their codes with types.

Refactoring becomes easier

Developers often desire to refactor a lot of things in their development process, but it touches many other code and files that are wary to modify. In TypeScript, such things can get refactored with a click of the “Rename symbol” command to your integrated development environment (IDE).

JavaScript being a dynamically typed language, the only way to refactor multiple files at the same time is by using the traditional “search and replace” function using regular expressions (RegExp). On the other hand, in the statically typed language like TypeScript, “search and replace” isn’t required.

Using the IDE commands like “Find all occurrences” and “Rename symbol,” one can see all occurrences in the app of the given function, class, and property of an object interface. TypeScript also helps developers find all instances of the refactored bit, rename it, and alert them with a compile error in case of the code mismatches post-refactoring.

TypeScript offers great advantages that we’ve not covered here. If you are keen to know more about ReactJS and mobile app development processes, connect with our expert developers and they shall help you understand and implement the new features.

When to use TypeScript?

Developers often recommend using TypeScript in one of the following cases:

If you’re planning to build an application that will be maintained over a long period, then choose TypeScript. It fosters self-documenting code. Thus, it helps other developers to understand the codes easily when they join an existing code base.

If you have to create a library, consider writing it in TypeScript. It helps code editors to suggest the appropriate types to developers who are using the existing libraries.

How to set up TypeScript in a modern React project?

One of the easiest ways you can choose is to hire a professional or outsource your ReactJS development project to a well-renowned ReactJS mobile development company like ours. We look through the project’s demands and requirements to fulfill the app’s purpose and retain your business customers. If you are more into DIY methods, here are the steps you need to follow to get started:

To create a new React app project, you can either run this command –

npx create-react-app my-app –folder-name


yarn create react-app my-app –folder-name

To add “TypeScript” in your new React app project, first install it and its respective @types:

npm install –save typescript @types/node @types/react @types/react-dom @types/jest


yarn add typescript @types/node @types/react @types/react-dom @types/jest
Next, rename the files (for instance, index.js to index. tsx), and you are good to restart your development server!

Final Thoughts

So far, we’ve seen how to set up TypeScript in a ReactJS app development project, its benefits, and its purpose. If you are looking for more insights on ReactJS mobile app development, we are here to help. Connect with our professionals today to learn more.


Why TypeScript is used in React?
It helps developers to write HTML code directly in a React app development project. Using TypeScript in React provides better IntelliSense and code completion for JSX.

What is the difference between TypeScript and ReactJS?
The only difference between the TypeScript and JavaScript react project is that its file extension ends with .tsx and the other ends with .js.

What is the purpose of TypeScript?
TypeScript help simplify JavaScript code, making it easier for developers to read and debug. It is open-source and provides highly productive development tools for JavaScript IDEs and practices like static checking. Also, TypeScript makes codes easier to read and understand.