HTML Code Runner — Run HTML CSS JS Online
Paste any HTML, CSS or JavaScript and run it instantly in a sandboxed preview. Load one of the preset examples or write your own snippet — perfect for testing ideas before publishing them.
Autosaved in your browser as you type. Your code never leaves your device.
HTML Code Runner FAQ
Common questions about running HTML online.
Yes, it is completely free. There is no registration, no watermark and no limit on how many times you run or download your code.
Your code is automatically saved to your browser's local storage as you type (key hr_runner_code). If you refresh or close the tab, your last version is restored the next time you visit.
Absolutely. Paste a full HTML document or just a fragment — the runner detects whether your code is a complete document and, if not, wraps it into a valid page automatically.
The presets demonstrate common patterns: a basic Hello World page, a styled button with hover effects, a JavaScript counter, a canvas animation with requestAnimationFrame, and a live fetch of JSON data from a public API.
No. Everything runs entirely in your browser. The preview is generated locally with a blob URL and nothing is uploaded anywhere.
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