JavaScript Tester
Run JavaScript and see its console output, in a fully sandboxed iframe.
Runs in a sandboxed iframe with no access to this page, cookies, or the network — safe to try code you don't fully trust. Only console.log/warn/error/info output and uncaught errors are captured. Nothing you write is sent anywhere.
What is JavaScript Tester?
Paste JavaScript, click Run, and see its console.log output — executed in a sandboxed iframe with no access to this page, your cookies, or the network, so it's safe to try code you don't fully trust.
FAQ
Yes — the code runs inside an iframe sandboxed with only allow-scripts (no allow-same-origin), so it can't read or modify this page, access cookies, or make meaningful network requests.
console.log, console.warn, console.error, console.info calls, and any uncaught errors — not return values or DOM changes.