If you have ever worked with TypeScript you know that it is nothing but JavaScript with some additional features. This means it’s a superset of JavaScript. However, TypeScripts features, functionality, and relatively easier coding make it a more suitable technology for developers. We bet you are curious about the difference between TypeScript and JavaScript. Bingo! Your search ends here my friend. In this blog, we will help you compare TypeScript vs JavaScript.


Here are some primary differences between TypeScript and JavaScript:

  • TypeScript supports interfaces but JavaScript doesn’t.
  • TypeScript has a feature known as ‘static’. But, JavaScript doesn’t support this feature.
  • JavaScript is a scripting language whereas TypeScript is an Object-oriented language useful in both front-end and back-end.
  • TypeScript provides full module support, JavaScript doesn’t support this feature.
  • Code of TypeScript is more reliable in comparison to JavaScript
  • TypeScript has an operational parameter function compatibility, whereas JavaScript does not.

You may also like:  Types of web development 

But before we hop on to a detailed comparison of TypeScript vs JavaScript, let’s have a peek into their respective history and understand them with their features.

History of TypeScript

Creator: Microsoft

Release Date: October 2012

Category: Open-source

Development Side: Both client and server-side

Extension: .ts

What is TypeScript?

TypeScript is a modern version of JavaScript. It is an Object-oriented language compiled to write clear and simple code. TypeScript is compiled with JavaScript easily without any issues. This is because it is a superset to JavaScript.

Features of TypeScript

  • Browsers can’t understand a word of the TypeScript, Hence, it is converted into Understandable JavaScript code. This process is known as trans-piled and browsers can easily interpret the code.
  • JavaScript is TypeScript- Changing the code from JavaScript to TypeScript is very easy. You change the extension from .js to .ts and your code is converted into JavaScript.
  • TypeScript code is useful anywhere. You can use any browser, device, or operating system can execute the TypeScript code smoothly. The code is not specific to any virtual engine or OS.
  • Library support TypeScript supports the JS library so the developers can easily utilize JavaScript libraries and can also call from other JavaScript libraries.

History of JavaScript

Creator: Brenden Eich (Netscape)

Release date: November 1996

Category: Standard Scripting Language 

Development Side: Client-Side

Extension: .js


What is JavaScript?

JavaScript is at the base of many Front-end frameworks which offer a responsive webpage at the client side. It is also known for transforming the web due to its dynamic capabilities.


The interactivity or dynamic nature of a webpage is because of JavaScript. It doesn’t require any resources from the server side.


JavaScript executes on your browser, and changes are made to it in real-time. It is useful with other technologies such as REST, XML, and more. 

Features of JavaScript

  • Server communication- before a page is sent to the server-side, it gives the option for validation of user input
  • Interaction- using JavaScript user experience is enhanced by creating an interface where a button generates a reaction as a result of mouse hovering.
  • Faster loading speed- as the changes are done in real-time. The developers don’t have to reload the pages to observe the changes.
  • User greetings- JavaScript has a feature where depending on the time and the appropriate date, greets the user.

Now we have points for extracting more differences between TypeScript and JavaScript.

TypeScript vs JavaScript:  Difference Between TypeScript and JavaScript


TypeScript vs JavaScript Code

Let’s see a sample of code for both TypeScript and JavaScript.


✦ TypeScript sample code:

var myvar  = //user input




return number + 100;



 The above TypeScript shows us that the result will always be a number. But what if a user inputs a character say “dog”? well in an ideal situation we alert the user that the operation is not possible! But, without that, the output will show dog100.


✦JavaScript sample code:



feeling = ’empty’;


feeling = 10;



This simple JavaScript Code declares a variable and assigns a value of empty (string) to it. Further, we can also assign a value of a different type (number) to the same string variable. JavaScript allows this and we can execute this code on any browser without any issues.


The HTML will look like this


<input type = “textbox” id = “howyoufeel”>


and the script will be:


feeling = document.getElementById(“howyoufeel”).value;


Unless we put explicit checks in this script, JS will continue to accept any value from the user and pass it on. Hence, you can put anything like 123, @.*$%, etc. in the feeling variable.  


TypeScript vs JavaScript: When to choose What?

In this section, by analyzing pros and cons of TypeScript and JavaScript, we will simplify the common choice issue i.e. when to use TypeScript? Or When to use JavaScript?

TypeScript Pros: When to use TypeScript? 

You should use TypeScript for the following benefits:

✦ Fast Error Detection 

TypeScript enables IDEs and the development environment to display errors and warnings while you code. Hence, spotting errors and correcting them in the early stages will not only save your time but also minimize runtime errors.

 ✦ Optional Static Typing

Unlike JavaScript TypeScript provides optional static typing. This means that once a variable is declared, it allows certain values and it can’t change its type. Additionally, the compiler gives developers alerts to any type-related errors while you code.

✦ Code Optimization

If you are looking for proper code optimization then, TypeScript needs to be your first choice. This is because it offers advanced features that improve the quality and readability of the code. Further, TypeScript offers Type Annotation, Generics, Intellisense, API Documentation, Namespaces, Interfaces, and so on.

✦ JavaScript Compatibility

TypeScript has great interoperability capabilities. You can use some well-known JavaScript libraries but you will require an Npm setup. Further, you can also rename your JavaScript file with .ts and it will work. For libraries, you need to check versions because type definitions must match the version of the library you are currently using.

✦ Portability and Flexibility

TypeScript is basically a superset to JavaScript and hence, it can run on any environment on which JavaScript runs. Further, typescript does not require any specific runtime environment or Virtual machine for execution. It supports all browsers, OS, and devices.


TypeScript is a flexible, scalable, and efficient programming language.

✦ Enhanced IDE support

The IDE support for TypeScript makes a developer’s job easy than before.


Firstly, it informs developers in real-time of type information. Secondly, it highlights compiler errors that are directly visible on the screen.


Finally, TypeScript allows refactoring of code without any issues.


These were the pros of TypeScript. So, when you are dealing with large codebases and require the above-mentioned benefits then, TypeScript is a better choice compared to JavaScript.


But what are the scenarios where TypeScript is not suitable?

TypeScript cons:

✦ Complicated Typing System

The static typing is not genuine in TypeScript. The feature is optional. Because TS is trans-piled into untyped JavaScript, there is always the potential risk of weird-type conversions.

✦ Compilation required

TypeScript requires compilation whereas JavaScript doesn’t. Here, the TypeScript compiler i.e. tsc consists of a watch mode that watches input files and compiles them to output files.

✦ Enlarged code

The enhanced code readability brought in by TypeScript along with type annotations has its own cons.


So firstly, a developer has to write more code and this evidently slows down the development process. Secondly, the developer requires some additional annotations that make TS files larger than those written in plain JS. Further, the difference in the number of lines of codes depends on a variety of factors.


The extra features will disappear after being transpiled and finally, the browser will execute plain JavaScript.

✦ Trans-piling 

Browsers can’t interpret the TypeScript code, so it transpiles into JavaScript before running. But, this process is highly automated and doesn’t require a lot of additional time.


In short, the downside of transpiling is that it requires an additional step before complete execution.

JavaScript pros: When to use JavaScript? 

✦ Small Projects 

JavaScript improves the performance of websites and web applications by minimizing the code length. With the use of built-in JavaScript functions for loops, DOM access, etc. the code contains less overhead.


Hence, JS is best suitable for small projects.

✦ Speed and Efficiency 

Since JavaScript is a client-side interpreted language, it reduces the compilations time for programming languages java. JS simply delivers swift execution of code and this saves time while connecting with the server.

✦ Interoperability 

JavaScript works fine with other programming languages, such as pearl, PHP, etc. Hence, developers prefer JS while app development. Also, one can easily embed JS into any webpage or inside another programming language because of its interoperability.

✦ Add-on Extensions 

JavaScript developers have the knack to write small segments of code that is useful in seamless integration with third-party apps on a webpage.


For example, add-ons like Greasemonkey (a Mozilla Firefox extension) allow developers to add snippets of predefined code in their code to save time and money. These add-ons help the developers to build JavaScript applications with much more ease in comparison with TypeScript.


These were some ideal benefits of JavaScript.


But, what are the disadvantages of using JavaScript?


JavaScript cons: 

✦ Client-side Security 

In general, JavaScript code is viewable to the end-user. This leads to malicious practices that include the usage of source code without authentication.


Further, any random developer can place some code into the site that will compromise the security of the data over the website.

✦ Browser support

The browser interprets JavaScript differently across different browsers. Hence, the code must be run on different platforms before publishing. Also, the older browsers are not compatible with new JavaScript functions, so, we need to check them as well.

✦ Debugging 

Although some HTML editors support debugging, they are not as efficient as other editors. Also, error detection is tough because the browser doesn’t show any errors. Hence, debugging in JS is hectic.

✦ Slow Bitwise Function 

JavaScript stores a number as a 64-bit floating-point number. Operators operate on 32-bitwise operands. Hence, JavaScript converts the number to 32-bits signed integers. Further, it converts these integers back to 64-bit JavaScript numbers.


This continuous conversion of the Bitwise function increases the time of execution.

✦ Rendering

A single code error can stop the rendering of the JavaScript code on the Website. From the user’s perspective, it appears as if JavaScript was never there. But, browsers are extremely tolerant of such errors.


TypeScript vs JavaScript Conclusion: Which is better?

Both TypeScript and JavaScript have their pros and cons. So choosing between TypeScript and JavaScript is a subjective matter.


But TypeScript does provide better features while working on complex projects. On the other hand, JavaScript is ideal for small web projects.


We hope that Webbybutter helped you with the TypeScript vs JavaScript comparison in detail. We do recommend TypeScript because of its popularity but we also know the power of JavaScript.      

TypeScript vs JavaScript: FAQs

Will TypeScript ever replace JavaScript? 

Well, short answer, no. TypeScript may be a superset of JavaScript but, it will never replace JavaScript because it is built on JavaScript and not suitable for all types of projects.


Does TypeScript run faster than JavaScript?

No, both TypeScript and JavaScript offer almost the same performance level. The only difference is that TS code is compiled to JS before execution.


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