JavaScript Playground

How the sandbox works

• Your code runs in QuickJS, a separate JS engine compiled to WebAssembly.
• The VM starts empty no DOM, no fetch, and no timers, just a JS interpreter.
• Each run gets a fresh VM with a 64 MB memory cap and an in-VM execution deadline: nothing carries over between runs
• eval() is disabled
• Runs are limited to 15 seconds and 64 KB of output; use Stop to end a run early