TypeScript – should you use it? Pros, cons and everything you need to know before deciding to use it.

TypeScript: Should You Use It? Pros, Cons, and Everything You Need to Know

If you’ve been coding in JavaScript for a while, you’ve probably come across developers singing praises of TypeScript. Some claim it’s a game-changer that improves code quality, while others argue it’s just added complexity. So, should you use it? In this blog, we’ll explore the pros, cons, and real-life examples of TypeScript to help you make an informed decision. By the end, you’ll have a clear idea of whether TypeScript is right for your next project. Let’s dive in!

I’ll be honest—when I first tried TypeScript, I felt like it slowed me down. Coming from JavaScript, where you could just write and run code without worrying about types, dealing with strict type annotations, setup headaches and debugging type errors felt frustrating compared to JavaScript’s simplicity.
But after using it extensively over the last 3.5 years, I can confidently say that TypeScript has completely changed the way I code. In a large-scale project, I realized the value it brings. One particular moment stood out: I was refactoring a function that was used in multiple places. In JavaScript, I would’ve been paranoid about breaking something, double-checking everything manually, fearing that a small change might break something in an unexpected part of the codebase. But in TypeScript, I confidently made changes, knowing that if anything broke, TypeScript would catch it immediately.
Over time, I realized that TypeScript isn’t just about “adding types”; it’s about building confidence in your code, and encourages better coding habits. It forces you to think more deeply about your data structures and ensures your codebase remains robust and maintainable.

What Exactly Is TypeScript (and Why Is Everyone Talking About It)?

Think of TypeScript as JavaScript’s smarter sibling. It’s a superset of JavaScript that adds optional static typing, meaning you can define the types of variables, function parameters, and return values. This helps catch errors early during development rather than at runtime.
At the end of the day, TypeScript code compiles into plain JavaScript, so it’s compatible with all browsers and JavaScript environments. It’s like upgrading from a standard toolset to one with precision instruments—it helps you work more efficiently and confidently.

In simple terms, it’s JavaScript with additional features, the most notable being static typing.
Why does static typing matter? Imagine you’re building a large JavaScript app, and somewhere in your code, you accidentally pass a string where a number is expected. The error doesn’t show up until runtime, and by then, it’s buried under layers of complexity. Static typing in TypeScript can catch these errors while you’re writing the code, making your development process smoother and less error-prone.
But don’t worry—TypeScript isn’t a whole new language. It’s still JavaScript at its core.

Why Do Developers Love TypeScript? OR Why TypeScript Is Getting So Popular

If TypeScript is so popular, there must be good reasons, right? Let’s break down the key benefits.

1. Fewer Bugs, More Confidence – TypeScript Catches Bugs Before They Catch You

One of the biggest reasons developers flock to TypeScript is its ability to catch errors early.
By enforcing type safety, TypeScript prevents common mistakes like passing a string where a number is expected. Here’s an example:

Without TypeScript:

function addNumbers(a, b) {
    return a + b;
}
console.log(addNumbers(5, "10")); // "510" instead of 15

With TypeScript:

function addNumbers(a: number, b: number): number {
    return a + b;
}
console.log(addNumbers(5, "10")); // TypeScript error: Argument of type 'string' is not assignable to parameter of type 'number' 

Without TypeScript, this error might go unnoticed until runtime, causing a headache. But with TypeScript static typing, you’ll spot the problem right in your code editor before you even run the program. This static typing ensures that you’re less likely to encounter bugs caused by type mismatches, saving you hours of debugging.

2. Improved Code Autocompletion and Refactoring

TypeScript’s integration with modern editors like VS Code makes the coding experience smooth and enjoyable. Features like autocomplete, intelligent suggestions, and refactoring tools boost your productivity.
For instance, consider this User interface:

interface User {
    id: number;
    name: string;
    email: string;
}

const user: User = { id: 1, name: "John Doe", email: "[email protected]" };

console.log(user.); // Autocomplete suggests 'id', 'name', and 'email'.

This autocomplete feature is a lifesaver, especially in large projects with complex data structures. It reduces the chances of typos and ensures you’re working with valid properties.
Ever been afraid to change a function in JavaScript, worried that it might break something elsewhere? With TypeScript, refactoring is safer. The compiler will alert you to any broken references, making large-scale code updates far less stressful.

3. Seamless Integration with JavaScript

TypeScript doesn’t require you to rewrite everything from scratch. You can gradually adopt it in your JavaScript project by renaming your .js files to .ts and adding types incrementally. This flexibility makes the transition much less daunting.

4. Easier Collaboration and Maintenance

In a team setting, TypeScript enforces consistency by ensuring everyone adheres to defined types. This is especially useful when onboarding new developers or maintaining a codebase months (or years) after it was written.
For example, if your API expects a specific payload structure, TypeScript helps ensure everyone on the team adheres to it:

interface CreateUserPayload {
    name: string;
    email: string;
    age?: number; // Optional property
}

function createUser(payload: CreateUserPayload): void {
    console.log(`Creating user: ${payload.name}`);
}

// Any deviation from the expected structure will throw an error during development.
createUser({ name: "John", email: "[email protected]" });

This consistency is invaluable in large-scale applications.

5. A Better Long-Term Investment

TypeScript is especially beneficial for projects that require long-term maintenance. Refactoring becomes less scary because the type system ensures you don’t accidentally break something.

6. It’s Backed by Industry Giants

TypeScript isn’t just a niche tool—it’s backed by companies like Microsoft, Google, Airbnb, and Slack. The fact that these tech giants rely on it for their large-scale applications speaks volumes about its reliability.

The Other Side: Why Some Developers Avoid TypeScript

No tool is perfect, and TypeScript is no exception. Here’s why some developers prefer to stick with JavaScript:

1. Learning Curve for Beginners

If you’re coming from plain JavaScript, TypeScript can feel intimidating. You’ll need to learn new concepts like interfaces, generics, and union types. For instance, the following TypeScript code might seem overwhelming to someone new:

For example, this simple JavaScript function:

function greet(name) {
    return "Hello " + name;
}

Becomes this in TypeScript:

function greet(name: string): string {
    return "Hello " + name;
}

While this added clarity is great, it can feel like extra work initially, especially for beginners.

2. Slower Development Speed

TypeScript adds an extra layer of complexity to your workflow. Writing types, debugging type errors, and maintaining type definitions can slow you down in the short term. If your team is used to rapid prototyping with JavaScript, TypeScript might feel like a speed bump.

3. Compilation Overhead

Unlike JavaScript, TypeScript code must be compiled into plain JavaScript before it runs. This extra compilation step can feel cumbersome for smaller projects, where the simplicity of JavaScript is often preferred.

4. Requires Additional Setup

TypeScript requires a compilation step, meaning you need to set up a build process using tools like tsc, Webpack, or Vite. While this isn’t a dealbreaker, it does add some overhead, especially for smaller projects.

When Should You Use TypeScript?

Here’s the million-dollar question: When does TypeScript make sense? Based on my experience, here are some scenarios where TypeScript shines:

• Large-Scale Applications: If your app has a lot of moving parts and a growing team, TypeScript’s type safety and tooling can save you from many headaches.
• Collaborative Projects: When multiple developers are working on the same codebase, TypeScript ensures everyone follows a consistent structure.
• Projects That Need Long-Term Maintenance: TypeScript makes it easier to maintain and refactor code over time, especially if the original developers leave the project.

However, if you’re working on a small prototype, a quick MVP, or a personal project, plain JavaScript is often enough. In these cases, TypeScript can feel like overkill.

A Real-World Example: Handling User Data

Imagine you’re building a simple user management system where a function retrieves user information. Here’s how it might look in JavaScript:

In JavaScript:

function getUser(id) {
    return fetch(`https://api.example.com/users/${id}`)
        .then(response => response.json())
        .then(data => data.name.toUpperCase()); // Potential error if 'name' is missing
}

At first glance, this function looks fine. However, what happens if the API response doesn’t include a name property? JavaScript won’t warn us, and the program might crash.

Now, let’s see how TypeScript makes this safer:

In TypeScript:

interface User {
    id: number;
    name: string;
}

async function getUser(id: number): Promise<string> {
    const response = await fetch(`https://api.example.com/users/${id}`);
    const data: User = await response.json();
    return data.name.toUpperCase(); // Ensured that 'name' exists
}

Here, TypeScript ensures that data must match the User interface, preventing runtime errors. If the API ever returns incomplete data, TypeScript will warn us during development instead of letting the error slip into production.

Key Differences Between JavaScript and TypeScript

A Practical Example: Refactoring a JavaScript App into TypeScript

Let’s say you have this basic JavaScript function:

function calculateArea(shape, dimensions) {
    if (shape === "circle") {
        return Math.PI * dimensions.radius * dimensions.radius;
    }
    if (shape === "rectangle") {
        return dimensions.length * dimensions.width;
    }
    return 0;
}

This works fine, but it’s prone to errors. What happens if someone passes an invalid shape or forgets a required property in dimensions? Let’s rewrite it in TypeScript:

type Shape = "circle" | "rectangle";  

interface CircleDimensions {  
    radius: number;  
}  

interface RectangleDimensions {  
    length: number;  
    width: number;  
}  

function calculateArea(shape: Shape, dimensions: CircleDimensions | RectangleDimensions): number {  
    if (shape === "circle") {  
        return Math.PI * (dimensions as CircleDimensions).radius ** 2;  
    }  
    if (shape === "rectangle") {  
        return (dimensions as RectangleDimensions).length * (dimensions as RectangleDimensions).width;  
    }  
    return 0;  
}

This version is safer and less prone to runtime errors. Plus, your editor will catch any incorrect usage!

Conclusion: Is TypeScript Right for You?

In my experience, TypeScript is an incredible tool when used in the right context. If you’re working on a large-scale application, a team project, or something that requires long-term maintenance, TypeScript is absolutely worth the investment. It may take some effort to learn, but the benefits far outweigh the initial struggles.
That said, if you’re working on a small personal project or need rapid prototyping, plain JavaScript might be a better fit. TypeScript’s added structure can sometimes feel like overkill for simpler use cases.
Ultimately, I encourage you to try TypeScript on a smaller project first. Get comfortable with its basics, and you’ll quickly see why so many developers swear by it.