Online TypeScript Compiler & Playground

When you press Run, the official TypeScript compiler loads in your browser (once, then cached) and transpiles your code to JavaScript locally. The resulting JS runs in a sandboxed Web Worker — same isolation as our JavaScript playground. No server is involved at any step.

The sandbox is locked down before your code runs: no DOM, and network APIs are disabled. So your TypeScript can compute and print via console.log, but it cannot make requests or reach our systems — it's a private, isolated scratchpad for learning and testing.

Execution is bounded by a 15-second timeout and worker isolation, so an infinite loop is terminated automatically without freezing the tab. Your code is wrapped in an async function, so top-level await works.

• TypeScript — official documentation
• MDN — JavaScript reference (the compiled output)

Compilation uses the official TypeScript compiler in your browser; execution uses your browser's JavaScript engine inside a Web Worker.