Online TypeScript Compiler

Write and run TypeScript code directly in your browser with this free online compiler. TypeScript is a superset of JavaScript that adds static type checking. Developed by Microsoft, it helps catch errors at compile time and improves code quality. This compiler lets you test TypeScript code instantly without installing the TypeScript compiler.

What is TypeScript?

TypeScript is a statically typed superset of JavaScript created by Microsoft in 2012. It adds optional type annotations, interfaces, enums, generics, and other features to JavaScript. TypeScript code is compiled (transpiled) to plain JavaScript that runs in any browser or JavaScript engine. It has become the standard for large-scale JavaScript development, with adoption by Angular, React, Vue, and many other frameworks. TypeScript improves developer productivity by catching errors early and providing better tooling support.

Key Features

• Static Typing: Catch type errors at compile time, not runtime.
• Interfaces: Define contracts for objects and classes.
• Generics: Write reusable, type-safe code.
• Enums: Define named constants for better code readability.
• 100% JavaScript Compatible: TypeScript compiles to standard JavaScript.

Basic TypeScript Syntax

// Interface definition
interface Developer {
  name: string;
  role: string;
  skills: string[];
}

// Function with types
function greet(developer: Developer): string {
  return `Welcome, ${developer.name}! You are a ${developer.role}.`;
}

// Generic function
function first<T>(array: T[]): T | undefined {
  return array[0];
}

// Enum
enum Language {
  TypeScript = "TypeScript",
  Python = "Python",
  Java = "Java",
}

// Type inference
const site = "LabsICT";
const year = 2025;

// Array and loop
const languages: Language[] = [
  Language.TypeScript,
  Language.Python,
  Language.Java,
];
languages.forEach((lang) => {
  console.log(`Learn ${lang} at ${site}`);
});

// Object usage
const dev: Developer = {
  name: "Bilal",
  role: "Founder",
  skills: ["TypeScript", "JavaScript", "Node.js"],
};

console.log(greet(dev));
console.log(`First skill: ${first(dev.skills)}`);

What Can You Build with TypeScript?

TypeScript is used for large-scale web applications, backend services with Node.js, and full-stack frameworks like Next.js and NestJS. Angular uses TypeScript exclusively. React and Vue have first-class TypeScript support. Companies like Microsoft, Google, Slack, and Airbnb use TypeScript for their web applications. It is also used for CLI tools, library development, and any project where code quality and maintainability are important.

Try It Yourself

Type your TypeScript code in the editor and click Run. The compiler supports interfaces, generics, enums, type annotations, and arrow functions. Use Copy to save, Reset to restore the example, and Share to generate a link.

Related Resources

Continue with our TypeScript learning track, try more online compilers, or browse tutorials for step-by-step guides.