Does this compile TypeScript or just check types?

It compiles and then runs the resulting JavaScript, so you see both type errors and real runtime output.

Can I use interfaces, generics and decorators?

Yes. Standard TypeScript language features are supported.

Is the TypeScript playground free?

Yes, free with no account required.

main.ts

Input

Output

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Online TypeScript Playground

Runs on TypeScript 3.7.4 · Free · No signup required

A free online TypeScript playground that actually runs your code rather than only type-checking it. Write TypeScript, compile it, and see real output — no local install, no tsconfig setup, no signup. That distinction matters for backend work: it is one thing to know a type is valid, and another to know the compiled JavaScript behaves the way you expected at runtime. Use it to test a generic you are not sure about, confirm how a union narrows, or check that an async function resolves in the order you think it does. Compilation and execution happen server-side, so you get both compiler errors and runtime output. Standard input is supported. If you are writing TypeScript for NestJS or Node services, the playground pairs with our backend projects and courses.

TypeScript Playground — Frequently Asked Questions

Does this compile TypeScript or just check types?: It compiles and then runs the resulting JavaScript, so you see both type errors and real runtime output.
Can I use interfaces, generics and decorators?: Yes. Standard TypeScript language features are supported.
Is the TypeScript playground free?: Yes, free with no account required.

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