SandboxJS

Safe JavaScript eval runtime

JIT Parsing

Tests compare SandboxJS against a proxied eval. A global bypassed flag is set to true if a test escapes the sandbox — highlighted in red. Blocked bypasses show as Error.

Performance

Sections

Sandbox Runner

Write JavaScript, keep it in the URL hash, and run it only when you press the button.

JavaScript Input

Options

forbidFunctionCalls forbidFunctionCreation haltOnSandboxError async

Execution Quota

ticks (blank = unlimited)

Scope / State

JSON object merged into sandbox scope

Idle —

✓ `globalThis.bypassed` is falsy.

Console

No logs yet.

Return Value

Run code to inspect the result.