Every time you start a new frontend project, you’re faced with a choice: JavaScript or TypeScript. It’s a debate that often leaves developers scratching their heads.

Over the years JavaScript has become a versatile web development engine. But it still has some issues, like dynamic typing and a lack of static checks.

To overcome these, TypeScript was introduced in 2012. It provides features such as static typing as well as improved tools that facilitate writing and maintaining code.

Ultimately, the purpose is to create applications that are high-performance, scalable, and easy to maintain.

Since, when selecting TypeScript vs JavaScript or trying to learn the difference between TypeScript and JavaScript, it is relevant to consider the language that suits the needs of your project.

In this article, we’ll explore the key differences between JavaScript and TypeScript, compare their strengths, and discuss how each can benefit your development process.

Let’s get started!

What is JavaScript?

JavaScript is one of the most common technologies on the internet. It has been and still is (one of) the key factors to develop interactive and dynamic web pages.

Today, it runs applications on almost every device. This includes Windows, macOS, Android, iOS, smart TVs, and more. Approximately 98.9% of websites or around 49.5 million use JavaScript on the client side.

JavaScript was created by Brendan Eich in 1995. Initially called LiveScript, it was later renamed JavaScript by Netscape to capitalize on the popularity of Java at the time.

JavaScript is easily used in conjunction with HTML and CSS to make the user interface components of a vast majority of websites. It can also be integrated with technologies such as XML and REST APIs.

Key Features of JavaScript:

• Flexible, dynamic, and cross-platform
• Lightweight and interpreted
• Weakly typed
• Supported by all browsers
• Uses JIT (Just-In-Time) compilation
• Works for both client-side and server-side development
• Supports asynchronous programming

What is TypeScript?

If you’re wondering, “What’s better than JavaScript?" TypeScript is the answer.

Developed by Microsoft, TypeScript is an object-oriented, open-source language. It is a superset of JavaScript with optional typing and compiles to native JavaScript. TypeScript can be used with Node.js and all browsers that implement ECMAScript 3 and later versions.

TypeScript files have the extension ".ts." Optional type annotations enable static type checking at compile time. TypeScript allows code to be both simple and easy to understand. It can be applied to both the client's side and the server's side applications.

To build scalable, error-free applications, hire TypeScript developers who are skilled in writing robust code using TypeScript’s powerful features. As the TypeScript adds capabilities to JavaScript, such as object-oriented programming, platform independence, and JavaScript library support.

Key Features of TypeScript: 

• Easy to maintain and boost productivity
• Full IDE support
• Supports static typing and annotations
• Simple debugging and early error detection
• Offers object-oriented features such as interfaces, inheritance, and classes

When to Use TypeScript Over JavaScript?

Choosing TypeScript over JavaScript is driven by the complexity of the project, the size of the team, and the future vision of the project. Here are some reasons to consider TypeScript:

Large Projects:

If size and maintainability are critical, then TypeScript is a great choice. Its static typing and object-oriented features help manage complexity.

Team Environments:  

In a team, the type system of TypeScript enforces uniformity and minimizes ambiguity, resulting in fewer errors and better team collaboration.

Error Prevention:

In TypeScript, errors are checked thoroughly at compile time, which enables you to identify and resolve the problems early, thereby saving time and effort in subsequent debugging.

Tooling Support:

Thanks to more advanced IDE capabilities such as auto-completing, refactoring, and real-time feedback of errors, TypeScript increases the developer's productivity.

Future-Proofing:

TypeScript includes modern JavaScript features like ES6 and ES7. This makes your code easier to maintain and adapt over time. Your project will be always up-to-date, which sets an important condition for future development of JavaScript or TypeScript projects.

When to Choose JavaScript Over TypeScript?

Deciding on whether to use JavaScript or TypeScript for a project. Here are some scenarios where using JavaScript instead of TypeScript can be the better choice:

Stable Testing Workflow:

If your team practices test-driven development (TDD) with JavaScript, switching to TypeScript may bring additional complexity. There is more value in stabilizing your workflow instead of jumping to new technologies in a shooting and seeing if it sticks.

Small Projects:

JavaScript is the perfect language to use for little things. It’s simple and easy to use. For small projects, the additional trouble of configuring TypeScript (including the compilation step) may not be worth it. Businesses aiming to take advantage of JavaScript's capabilities, prefer to hire JavaScript developers. Their proficiency ensures that your web applications are not only functional but also optimized for performance and user experience

Build Tools Needed:

Unfortunately, unlike JavaScript, TypeScript has a compilation step to take code written in TypeScript and convert it to JavaScript. If your project does not require this added complexity, sticking to JavaScript can help streamline the process by removing additional build tools from the equation.

No Compilation Step:

JavaScript doesn’t need to be compiled, unlike TypeScript, which means you run it directly in the browser. This enables rapid iterations and real-time responses, which makes it perfectly suited for fast-paced development.

Framework Support:

JavaScript is rich in frameworks and libraries. Using them for quick development, JavaScript could be more productive. On the other hand, other frameworks or libraries may not play so nicely with TypeScript.

TypeScript vs JavaScript: Pros & Cons

The debate between TypeScript and JavaScript is common in web development. Each has its strengths and weaknesses, making them suitable for different projects. Here’s a simple comparison of TypeScript and JavaScript to help you choose the right one for your next project.

TypeScript

Pros:  

• Static Typing: Variable types and function types are expressible in TypeScript. Due to this, faults are detected in a preliminary step and consequently, neither runtime failures nor good code quality can be reached.
• Better Tooling: TypeScript provides auto-completion, real-time feedback, and refactoring capabilities. This improves productivity and speeds up development.
• Maintainability: (Strict type and interface usage lead to highly maintainable code, especially in large-scale projects). It enables the writing of code that is optimized and runs large applications.
• Backward Compatibility: TypeScript is a superset of JavaScript. This means existing JavaScript code works in TypeScript. As such, you can further and further extend its application without altering your code.

Cons:  

• Steeper Learning Curve: For those who do not know TypeScript types and interfaces, it is tricky. This may slow initial development.
• Compilation Step: TypeScript must be converted into JavaScript before it runs. At this level, the number of operations in the manufacturing process is increased, and therefore the time to manufacture is decreased.
• Potential Overhead: If it is so, the generated JavaScript code is more verbose as a result of its class type which may impact performance in certain cases.

JavaScript

Pros:

• Simplicity and Flexibility: JavaScript is dynamically typed, so prototypes and dynamic code can be easily prototyped and written. There’s less need for boilerplate code compared to TypeScript.
• Immediate Execution: JavaScript is an uncompiled language, and it can be executed directly in the browser. This allows for faster iterations and quick feedback.
• Widespread Adoption: JavaScript is supported by all browsers and platforms. It has an impressive ecosystem of libraries and frameworks that have contributed to its capability.

Cons:  

• Runtime Error Detection: Errors in JavaScript are caught only at runtime. This makes debugging harder, especially in larger applications.
• Less Structure: Since mobility brings challenges in JavaScript control for rapidly expanding projects, it points to an equivocation caused by flexibility. Without strict typing, type-related issues may arise.
• Limited Tooling: However, JavaScript is not able to deliver the fluent features of a statically typed language with rich benefits in the form of a curated set of development tools as is available with typings, without the need for static typing.

Key Differences Between TypeScript and JavaScript

Let’s take a look at the key differences between TypeScript and JavaScript.

Performance

Performance plays a crucial role in programming. Both TypeScript and JavaScript are similar in performance. As TypeScript is converted into JavaScript, the output will be. There may be a minor overhead as a result of the additional compilation stage in TypeScript. But, modern compilers are optimized for high performance.

Syntax

Syntax is one of the significant contrasts between TypeScript and JavaScript. JavaScript is dynamically typed, i.e., variables of types are determined at runtime. This allows for flexible and concise code. 

However, static typing with type annotations is provided by TypeScript in the form of type annotations at compile time. This enhances code readability and offers an earlier chance for identifying errors, especially in large projects.

File Extension

File extensions help distinguish different file types. Typescript files have a ".ts" extension and javascript files have a ".js" extension, respectively. This difference allows developers and build tools to determine and work with the respective files.

IDE Support

Integrated Development Environments (IDEs) are valuable with properties to help to increase the productivity of work. It is a fact that TypeScript provides better IDE support than JavaScript does, due to the use of static typing. 

In particular, IDEs (e.g., Visual Studio Code) provide more features (e.g., IntelliSense, error tracking, and code refactoring) for the TypeScript programming language. Yet, for JavaScript as well, the IDE is not supported, but the deep level of advanced tooling that TypeScript provides is also available for it.

Complexity

The complexity of a programming language has to do with the ease of understanding and maintaining. The dynamic typing of TypeScript is less convenient to work with than the one in JavaScript. It improves code quality and adds structure. 

On the other hand, it needs developers to acquire new knowledge (e.g., type annotation and interfaces). JavaScript developers can be exposed to a learning curve when moving to TypeScript.

Readability

Readability is important for collaboration and long-term project success. TypeScript is often more readable than JavaScript due to types, i.e., type annotations. These annotations serve as a record that facilitates the specification of variable types and function signatures. The interface is, also, supported in TypeScript, to make the code more understandable, especially in the case of bigger applications.

Compatibility

In using a new language, it should be able to easily integrate with existing work. TypeScript fits this need perfectly. It does JavaScript compilation, so you are not limited in the type of JavaScript library or framework you can use. 

This matchup facilitates seamless integration of TypeScript into active projects. You can also gradually migrate from JavaScript to TypeScript.

Tools and Frameworks

The availability of tools and frameworks greatly impacts development. TypeScript enjoys high endorsement from leading frameworks such as Angular1, React, and Vue.js. 

These frameworks offer tools and templates tailored for TypeScript. They make the development process easier and help you get going very quickly. The static typing of TypeScript improves its suitability for tools that perform analysis and testing on code.

Learning Curve

The learning curve is what determines how fast the engineers can learn a language. JavaScript has a more shallow learning curve, because of its more conciseness and dynamically typed form. Developers can start writing code without much preparation. 

Nevertheless, because of the static typing system of TypeScript, its learning curve becomes steeper. Developers must get familiar with type annotations and other aspects specific to TypeScript. Still, however, for many developers, the investment is well worth it given the gains in code quality and tooling.

Quick Comparison: TypeScript vs JavaScript

JavaScript is easier to debug as it directly executes the code in browsers. TypeScript, however, will compile the code to JavaScript before run time. Although JavaScript is more suitable for web development projects, TypeScript may not always be the best choice. Choosing TypeScript or JavaScript can be tough. Here's a quick comparison of essential criteria:

Wrapping Up

Both JavaScript and TypeScript have distinct advantages. JavaScript is great for fast movements, especially for small-medium projects.

TypeScript's static typing and intricate frameworks yield great benefits, especially among larger-scale applications with a focus on maintainability and scalability. The choice between JavaScript vs TypeScript depends on your project’s needs. 

Having trouble deciding which language to use in your web development project? Reach out if you are uncertain about JavaScript or TypeScript. Let us show you how you can use the correct tools to turn your vision into a reality.