Local sandbox
JavaScript scratchpad
Type JavaScript and run it in a WebAssembly sandbox on your device: no account, no server, no access to the page, the network, or your files. It runs your snippet only, never any uploaded code.
Changes are saved on this device after you begin editing.
What this sandbox is
The scratchpad runs your snippet in a QuickJS engine compiled to WebAssembly, entirely on your device. The sandboxed engine has no DOM, no network access, and no access to this page or your files. It evaluates plain JavaScript, shows anything you log with console.log, and prints the value of the last expression as the result. Nothing you type is sent to a server, and no account is involved.
Limits, stated plainly
A one-second wall-clock deadline stops infinite loops, a 32 MB memory cap stops runaway allocation, and snippets are limited to 20,000 characters. Because the sandbox is deliberately isolated, browser APIs such as fetch, document, and timers are not available. This is a place to try language ideas, not a full runtime. The engine loads on your first run, so the page stays light until you use it.
Good uses for it
Check what an array method actually returns, test a regular expression against a string, work through an exercise from a tutorial, or verify a one-liner before using it somewhere real. If you are studying a programming topic elsewhere on Novus Learn (say through a web article or a textbook), the scratchpad is a quick way to test what you just read. For structured lessons, see tutorials and help.