TypeScript vs JavaScript | What is the main difference?

TypeScript vs JavaScript

Whether you are new to programming or are just new to the coding languages of the “script” family, you will find a lot of information below. Here we are going to discuss the difference between TypeScript and JavaScript.

Let’s start by discussing JavaScript, the core language providing most global websites with an interactivity element. 

Further, you will learn why TypeScript is introduced and always used so tightly with its “script-cousin” JavaScript.

What is JavaScript used for?

JavaScript is the scripting coding language that helps to add interactive elements to web pages. Its complex features help make websites alive out of the static displays. You can add interactive maps, animated 2D/3D graphics, scrolling videos, and similar details with JS.


Together with HTML and CSS, JavaScript is another necessary element for building website front-ends. HTML accounts for the website’s structure, CSS adds visual style, and JavaScript is responsible for the dynamic content. 

Each time you load a web page, those three languages (presented in chronological order) start working, as a result of which the web page receives its final version of UX. 

JavaScript is good because it’s a client-side programming language, which means JS runs directly from the user’s browser. Also, programmers can use it with various APIs (Application Programming Interfaces) to make the coding process significantly easier.

How do APIs help?

They are the functionality built on top of JavaScript, which enhances programmers to utilize JS’s power better. Particularly, instead of writing the code for each element, APIs allow the users to use ready code building blocks and construct more complex web page functionality. 

The benefits of JavaScript

  • JS has a specially designed mechanism for small scripts
  • Compiled JS runs in any browser
  • It can be extended for writing larger apps
  • JavaScript is a lightweight, object-oriented coding language
  • JS has a robust testing workflow
  • It’s easy to understand and learn for both users and developers

Well, so what are the drawbacks of JavaScript that TypeScript was designed for compromising?

Before we move on to the “TypeScript vs JavaScript” section of this article, let’s list some of JS’s disadvantages. 

Not the strongest security

If we say the language is easy to learn and understand for users, this means it’s also easily accessible for “bad users” like hackers. JS code is easily viewable to any user, making the web page highly fragile to malicious attacks. Anyone can use the source code without authentication and insert some code into the website. 

Rerunning on different platforms

We mentioned compiled JS can run on any browser. Still, web platforms interpret the JavaScript code in different ways, usually based on the browser’s latest update status. That’s why you can sometimes need to double to run the JS code on any new platform. Sometimes, you might have to accept certain functionalities will not work for a specific browser. 

Sometimes it might take slightly more to run

The processes happening behind the curtains in JavaScript might sometimes slow down the time it needs to run. Particularly, JS stores numbers in a 64-bit floating-point number. As operators rely on 32-bitwise operands, JavaScript has to convert the numbers into 32-bit integers to operate on them and convert them back to 64-bit numbers. This usually takes time. 

So, what are the ways TypeScript improves JavaScript?

TypeScript vs JavaScript

Let’s start with “What is TypeScript and how did it emerge?” first. 

TypeScript was first introduced to the public in 2012, while JavaScript had already been a successful coding language and one of the top ones in the industry since its establishment in 1995. 

Microsoft developed the TypeScript, and it’s continuously improving its features with the capacity of working times faster, supporting ES6 modules, having tools like key and lookup types mapped types, and many more. 

To keep it short, JavaScript is considered to be a modern age JavaScript coding language. It helps write clear and straightforward JS code and develop robust software and deployability with a standard JavaScript application. That’s why many programmers’ advice is that if you have enough time and resources, it’s better to study both TypeScript and JavaScript, rather than separately one of them. 

For larger-scale projects, you will most probably need the help of TypeScript, so we offer you to:

TypeScript vs. JavaScript

Scripting language for interactive websitesSuperset of JavaScript
Doesn’t need to be compiledNeeds to be compiled
Better for small size projectsBetter for larger projects due to generics & JS features
Offers the opportunity to create code without a built stepMost of the npm packages either have a static type definitions or external ones that can be easily installed
Doesn’t have a prototyping featureHas a prototyping feature
No need for annotationsThere is a need to constantly annotate the code
Does not support modulesSupports modules
Dynamically typed. The errors are identified during the runtime of the code. Statically typed. The declared variable does not change its type. 
Does not have interface or data typesHas interfaces and data types

TypeScript, in its turn, has disadvantages

Practically, the duo of TypeScript and JavaScript is one of the most powerful combinations you can use for creating powerful front-end projects for your web pages. However, there are certain drawbacks of TypeScript you should keep in mind while working with it. 

  • As mentioned above, TypeScript needs to be compiled. That takes additional time and makes the coding process longer. 
  • If the application written on TypeScript is run in the browser, there will be a requirement to transform TypeScript into JavaScript.
  • Before fully constructing full-scale projects via TypeScript, you will need to spend time and effort learning JavaScript.