Capability 05

Run JavaScript in an isolated worker

Edit the code and it actually runs. Break it and you get a real error, not a canned one.

JavaScript
Web Workers
Blob URLs

sandbox

live execution · Web Worker · 3 second kill switch

ready SANDBOX · no data leaves your browser unencrypted

Genuine execution. Your code runs in a dedicated Worker with no DOM, no network access, and a hard three second timeout, so an accidental infinite loop terminates instead of freezing the tab.

Load the ‘Try to break it’ example from the toolbar. The error it reports is produced by the same engine that renders this page.