JavaScript, with types that catch mistakes early

TypeScript Compiler Online — Run TypeScript Code in Your Browser

TypeScript adds static types on top of JavaScript, catching a whole category of bugs before your code ever runs. It's become the default for any JavaScript codebase serious enough to need refactoring safely.

function main(): void {
  console.log("Hello, world!");
}

main();

What people use TypeScript here for

• Checking how a type definition or generic actually behaves
• Testing TypeScript syntax without a tsconfig and build step
• Following a TypeScript tutorial without a local Node setup

No installs, no signup

Code you write here runs on a real, self-hosted Judge0 execution backend — actual TypeScript compiler or interpreter output, not a simulation. Your code passes through a real tsc type-check before running, so type errors show up the same way they would in your own build. See the full list of supported languages or read more about how AnyCompiler works.