There are so many new programming languages popping up seemingly every year that we’ll forgive you for getting mixed up sometimes. In the case of one relatively young language that’s skyrocketed in popularity over the past few years, it’s even easier to mix it up with something more prosaic: TypeScript.

And, yes, the first time even some of us heard that name, we, too, thought it was what we used to write shopping lists on our phones.

But TypeScript has nothing to do with old-school fonts or your dreams of penning a screenplay starring Vin Diesel saving the day with a typewriter. Instead, it’s a programming language that was developed as a way to extend the utility of the most popular programming language in the world, JavaScript.

TypeScript vs. JavaScript

If you want the most clear-cut definition, TypeScript is a statically typed, object-oriented programming language built on top of JavaScript. It was developed and released by Microsoft in 2012, which still maintains it. A decade later, TypeScript ranked fifth in Stack Overflow’s annual survey of most popular languages for both amateur and professional developers. 

Because TypeScript is a superset of JavaScript, any valid JavaScript code is also valid TypeScript code. But TypeScript is like a supercharged version of JavaScript: TypeScript provides optional type annotations that can catch errors at compile time rather than run time. This generally means more easily maintained and bug-free code and projects that are easier for other coders to work on later on — the type annotations means changes are made in a more controlled manner. (And the annotations are completely optional.)

There’s more: TypeScript adds to JavaScript features such as classes, interfaces and modules. Because of these additions, developers can write code in a more object-oriented style and add more structure to the system architecture. TypeScript also has better support for modern JavaScript features, like async/await, and can also be used with popular front-end frameworks such as Angular and React.

What is TypeScript used for?

TypeScript was made especially for large web applications, but it can be used in a variety of software development projects, including web applications, mobile apps and desktop applications, and its improved code quality and maintainability, reduced development time and support for modern features make its popularity a no-brainer.

Well-known companies using TypeScript include Slack, TechStack, DoorDash, Accenture, Medium, Airbnb, Asana, Lyft and, naturally, Microsoft.