Is this a JavaScript compiler?

Yes — for quick snippets. PeachTools compiles and runs your JavaScript in the browser using your engine's built-in parser. It is ideal for testing logic, not for building production bundles.

Can I test JavaScript online without installing Node?

Yes. Paste code, press Run, and see console output instantly. No Node.js, npm, or server-side setup required.

Is my JavaScript code sent to a server?

No. Your code is executed entirely in your browser inside a Web Worker. PeachTools never receives or stores your snippets.

Does this support TypeScript?

Yes. Toggle TypeScript in the playground or use the dedicated TypeScript Playground tool. Types are stripped locally with Sucrase before JavaScript execution.

Can my code access the PeachTools page or cookies?

No. User code runs in an isolated worker with no DOM access. It cannot read PeachTools cookies or modify the page.

Can I use fetch() or async/await?

Yes. Async/await and fetch run in the isolated worker using your browser's network stack — PeachTools does not proxy requests. The remote API must respond with CORS headers that allow your browser origin; public test APIs like jsonplaceholder.typicode.com work, but many internal or cookie-authenticated APIs will be blocked by the browser.

Is this a secure sandbox for untrusted code?

This playground is designed for learning and quick snippets, not for running malicious or secret-bearing code. Do not paste production credentials.

What JavaScript version is supported?

Your browser's built-in JavaScript engine (modern ECMAScript). Features depend on the browser you use.

JavaScript Playground

Run, test, and debug JavaScript snippets in your browser

Run and test JavaScript online in a private, in-browser sandbox. Use it as a JS compiler or snippet tester — execute code with console output in an isolated Web Worker. Your code never uploads to PeachTools.

Also known as: js compiler · javascript compiler · javascript tester · js tester · test javascript online · run js online

100% In-Browser & Private — your data never leaves this device

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How to use the JavaScript Playground

Paste JavaScript into the editor, or click Load sample to try a demo snippet.
Optionally switch to TypeScript — PeachTools transpiles locally before running.
Press Run or use Ctrl+Enter (Cmd+Enter on Mac) to execute in an isolated Web Worker.
Review console output and errors in the Output panel. Use Stop to cancel a long run.

FAQ

Is this a JavaScript compiler?: Yes — for quick snippets. PeachTools compiles and runs your JavaScript in the browser using your engine's built-in parser. It is ideal for testing logic, not for building production bundles.
Can I test JavaScript online without installing Node?: Yes. Paste code, press Run, and see console output instantly. No Node.js, npm, or server-side setup required.
Is my JavaScript code sent to a server?: No. Your code is executed entirely in your browser inside a Web Worker. PeachTools never receives or stores your snippets.
Does this support TypeScript?: Yes. Toggle TypeScript in the playground or use the dedicated TypeScript Playground tool. Types are stripped locally with Sucrase before JavaScript execution.
Can my code access the PeachTools page or cookies?: No. User code runs in an isolated worker with no DOM access. It cannot read PeachTools cookies or modify the page.
Can I use fetch() or async/await?: Yes. Async/await and fetch run in the isolated worker using your browser's network stack — PeachTools does not proxy requests. The remote API must respond with CORS headers that allow your browser origin; public test APIs like jsonplaceholder.typicode.com work, but many internal or cookie-authenticated APIs will be blocked by the browser.
Is this a secure sandbox for untrusted code?: This playground is designed for learning and quick snippets, not for running malicious or secret-bearing code. Do not paste production credentials.
What JavaScript version is supported?: Your browser's built-in JavaScript engine (modern ECMAScript). Features depend on the browser you use.