How to Convert a JavaScript Project to TypeScript in 2025

As development practices continue to evolve, many developers are opting to convert their JavaScript projects to TypeScript. The benefits such as improved code quality, easier refactoring, and enhanced code readability make TypeScript an attractive option for modern web development. In this guide, we will walk you through converting a JavaScript project to TypeScript in 2025.

Step 1: Install TypeScript

Start by installing TypeScript globally on your machine if you haven't done so already. Open your terminal and run:

npm install -g typescript

Step 2: Initialize a tsconfig.json

Navigate to your project directory and create a tsconfig.json file. This file will house your TypeScript configuration settings:

tsc --init

Step 3: Rename Your .js Files to .ts

Change the extension of all your JavaScript files from .js to .ts. This tells the TypeScript compiler to handle these files, and you'll begin to see some benefits of TypeScript's static typing.

Step 4: Address Type Errors

Once files are renamed, TypeScript will likely flag several type errors. Begin updating your code to resolve these errors by providing explicit types. You can refer to this typescript momentum calculation guide for detailed examples of using TypeScript's type system effectively.

Step 5: Utilize TypeScript Features

Take full advantage of TypeScript’s features like interfaces, enums, and generics to improve your codebase. This not only enhances the readability and maintainability of your code but also prepares your project for future updates.

Step 6: Compile Your TypeScript Code

Compile your TypeScript code to JavaScript using the TypeScript compiler. Run the following command in your terminal:

tsc

If you wish to learn more about converting TypeScript back to JavaScript, visit this typescript to javascript conversion discussion forum for insights.

Conclusion

By converting your JavaScript project to TypeScript, you pave the way for a more robust and maintainable codebase. Not only does it streamline your development process, but you also join a growing community of developers who recognize the advantages of TypeScript. For more information on why you should choose TypeScript over JavaScript, check out this article on typescript vs javascript.