JavaScript Compiler

Write and run JavaScript online inside an isolated, stoppable Web Worker for quick experiments and debugging.

The interactive workspace opens when JavaScript is available. Instructions and related guides are readable below.

About JavaScript Compiler

Run JavaScript snippets in a stoppable browser Web Worker.

Important limitations

Code runs in an opaque-origin sandbox without access to site storage or outbound network, including in nested workers. It has no page DOM or Node.js runtime. Use HTML Live Preview for document/window examples. Do not run code you do not trust.

Use these browser runtimes for short examples and learning. They are not full local development environments. Check runtime limitations before pasting project code, and never include credentials or code you do not trust.

Read about data handling and clearing saved local work

Practical guides

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