JavaScript Playground

An in-browser scratchpad for running a snippet of JavaScript and inspecting its console output. Your code is compiled with `new Function(code)` and executed synchronously; console.log, console.warn, console.error, and console.info are temporarily intercepted so their arguments are captured, formatted (objects JSON-stringified), and rendered in color by level. The tool also reports execution time in milliseconds and surfaces any thrown error in a red banner.

1. Replace the default `// Write your JavaScript code here` text in the Code Input textarea with your own snippet. 2. Click Run. Execution time appears next to the button as `Executed in X.XX ms`. 3. Inspect the Console Output card: each captured call is shown on its own line, color-coded — log (foreground), warn (yellow), error (red), info (blue). Objects are pretty-printed as 2-space JSON. 4. If the snippet throws, the exception message appears in a red error banner above the Console Output card and no console output is shown for that run.

Important behaviors to know before you rely on results: - Code is run via `new Function(code)()` in the page's real global scope — it is NOT a hardened sandbox. The tool itself warns about this with a yellow Security Warning banner. Do not paste untrusted code. - The four console methods are replaced for the duration of the run and restored in a `finally` block, so capture is scoped to your snippet only. - Argument formatting: `null` renders as the literal "null", `undefined` as "undefined", objects via `JSON.stringify(arg, null, 2)` (falling back to `String(arg)` if stringify throws, e.g. for circular structures), and primitives via `String(arg)`. Multiple arguments per call are joined with a single space. - There is no module/await support — async code will not block the timing measurement, and ESM `import` statements will throw.