JavaScript vs TypeScript in 2024

JavaScript is a lightweight, interpreted programming language that runs in web browsers. It powers dynamic behavior on websites and web applications. JavaScript was created in 1995 and has gone on to become one of the core technologies of the web.

What is TypeScript?

TypeScript is an open-source typed superset of JavaScript developed by Microsoft. It adds optional static typing, classes, interfaces, and other features to standard JavaScript. TypeScript code must be transpiled to plain JavaScript code before it can run in browsers. TypeScript was first released in 2012.

Developers frequently debate technology choices while building applications. JavaScript and TypeScript are two popular options that often elicit strong opinions on either side.

Key differences at a glance

• JavaScript is dynamically typed while TypeScript supports static typing
• TypeScript code must be compiled to JavaScript but JavaScript runs natively
• TypeScript adds features like classes, interfaces, and generics that do not exist natively in JavaScript
• TypeScript provides more tooling, and IDE support and helps catch errors during development

Popularity and usage

JavaScript popularity and usage

JavaScript remains the most popular programming language globally and runs on over 97% of websites. The rise of frameworks like Node.js, React, and Angular has fueled JavaScript adoption. Its dynamic nature makes JavaScript flexible and versatile for web development.

TypeScript growth and adoption

From humble beginnings, TypeScript has become very popular. The 2021 StackOverflow poll found TypeScript to be one of the programming languages growing fastest in the world. TypeScript has recently passed C# and PHP in total usage on GitHub.

TypeScript has been adopted by many prominent tech giants and startups including Microsoft, Google, Amazon, Facebook, Twitter, Airbnb, Netflix, Uber, and Lyft.

Features comparison

Syntax

TypeScript syntax is a superset of JavaScript syntax for the most part. Some differences include support for features like classes, interfaces, generics, tuples, and enums.

Static typing

A core difference between the two languages. TypeScript brings static types to JavaScript allowing developers to annotate variables and function parameters with types. This catches many errors during development that would otherwise crop up during runtime in JavaScript.

Compilation

TypeScript requires an additional build step to transpile code to JavaScript. JavaScript runs natively without any compilation.

TypeScript offers stronger tooling and IDE integration including excellent support in VS Code. Features like intelligent code completion and reliable refactoring help accelerate development.

Code quality and reliability

TypeScript’s focus on type safety nets many bugs early. Features like strict null checks further aid writing clean, less error-prone code vs plain JavaScript.

Development experience

Overall, TypeScript offers a superior developer experience with great editor tooling, helpful error checking, easy refactoring, top-notch Intellisense, and code navigation features.

Performance

Runtime performance

Performance is nearly identical for plain JavaScript vs TypeScript compiled to JavaScript according to benchmarks. At runtime, any performance gains from static types are offset by TypeScript’s heavier code emission.

Build time

TypeScript generally improves iteration speed by catching errors early although the compilation step does add to build time. For very large codebases, build time may be noticeably slower compared to JavaScript.

Community and resources

Open-source ecosystem

JavaScript has the largest ecosystem of open-source libraries and tools on npm. TypeScript supports popular JavaScript libraries like React. There are also 10,000+ TypeScript-specific libraries but the ecosystem is smaller compared to JavaScript.

Learning resources

There is an abundance of learning material available for JavaScript given its long history and popularity. Quality TypeScript resources are also easily available although not yet to the same extent.

Developer Community

JavaScript has an enormously active global community and still sees faster growth in new developers taking it up. The TypeScript community is smaller but rapidly expanding as well.

Use cases and industries

Web development

Both JavaScript and TypeScript are commonly used for web development. JavaScript remains the first choice for simpler websites. For complex web applications, TypeScript brings advantages like early error checking, code navigation, and refactoring support.

Mobile app development

JavaScript is the native language for React Native used widely in mobile development. TypeScript provides an easy transition for developers used to strongly typed languages on mobile platforms wanting to use React Native.

Desktop applications

TypeScript has emerged as a great choice for building performant desktop apps with Electron. The typing system catches more errors during development compared to JavaScript.

Game development

TypeScript delivers value in large game engines like Babylon.js by providing code quality, tooling, and development experience benefits over vanilla JavaScript.

Key Takeaways

When to choose JavaScript

• Building simple websites where dynamic behavior is needed
• Quick prototyping and creating MVP versions
• Prioritizing broad browser compatibility

When to choose TypeScript

• Complex web applications with sizable codebases
• If the team prefers strictly typed languages
• For improved tooling, code navigation, editor support
• When code quality, stability, and scalability are critical

FAQs

What big companies use TypeScript?

Microsoft, Google, Amazon, Facebook, GitHub, Airbnb, Netflix, Uber, and Lyft are some big tech companies using TypeScript extensively.

Is TypeScript fully compatible with JavaScript?

Yes, TypeScript is a superset of JavaScript and compiles down cleanly to JavaScript. All valid JavaScript code can run as TypeScript without issues.

Does TypeScript offer better performance than JavaScript?

There is little to no difference in runtime performance. TypeScript aims to aid development velocity and code quality rather than improving benchmark runtime metrics over JavaScript.

Is the TypeScript learning curve steep for JavaScript developers?

The learning curve is gentle. Most JavaScript concepts apply as is. Learning TypeScript mainly involves getting used to the new type system through annotation and tooling.

Which IDEs support TypeScript best?

Visual Studio Code has excellent support through internal tooling and various plugins. JetBrains IDEs like WebStorm are also very popular for TypeScript development.