Run JavaScript, TypeScript, Python, PHP online
Run JavaScript, TypeScript, Python or PHP and see the result instantly, 100% in your browser.
JS/TS: isolated Web Worker execution. Python (Pyodide) and PHP (php-wasm): the WebAssembly runtime is downloaded from a CDN on first run (a few MB), then everything runs locally — your code is never sent to a server.
🔒 100% client-side — no data sent
Write JavaScript, TypeScript, Python or PHP and run it instantly to see the output. JS and TS run in an isolated Web Worker; Python (Pyodide) and PHP (php-wasm) via WebAssembly, loaded on demand. Everything runs 100% in your browser — your code is never sent to a server.
What is it for?
- ▸ Test a JavaScript, Python or PHP snippet without installing anything
- ▸ Check how a TypeScript function behaves
- ▸ Learn and experiment with several languages live
- ▸ Debug an isolated algorithm client-side
FAQ
Is my code sent to a server?
No, everything runs locally in your browser. For Python and PHP, only the WebAssembly runtime is downloaded from a CDN on first run; your code itself never leaves your machine.
Which languages are supported?
JavaScript and TypeScript (instant), Python (via Pyodide) and PHP (via php-wasm), loaded on demand on the first Run click.
Why is the first Python/PHP run slower?
The WebAssembly runtime (a few MB) is downloaded and initialized once on first run, then cached for subsequent runs.