HTML Code Runner

Run HTML, CSS and JavaScript instantly in Chrome's Side Panel.

HTML Code Runner lets you write, preview, and debug HTML, CSS, and JavaScript directly inside Chrome’s Side Panel — without opening a separate tab or leaving your workflow. This extension is the companion Side Panel experience for HTMLCodeRunner.com. Your code runs locally on your device in a secure sandboxed preview. No login required. What you can do • Write complete HTML documents with embedded CSS and JavaScript • Preview results instantly in a sandboxed live preview pane • Inspect console.log, console.info, console.warn, and console.error output • Catch JavaScript runtime errors without crashing the editor • Copy your code or download it as index.html • Enable Auto Run to refresh the preview as you type • Use dark or light themes, adjustable font size, tab size, and word wrap • Open selected text from any webpage via the “Open in HTML Code Runner” context menu • Jump to HTMLCodeRunner.com or More Tools when you want the full website toolkit Keyboard shortcuts • Ctrl/Cmd + Enter — Run code • Ctrl/Cmd + S — Save code locally • Ctrl/Cmd + Shift + R — Reset to the starter document • Escape — Close dialogs Privacy Your code stays on your device. HTML Code Runner does not upload your source to a server, does not require an account, and does not include analytics or tracking. Preview execution is isolated from Chrome extension APIs. Perfect for • Students learning HTML, CSS, and JavaScript • Developers prototyping quick snippets • Teachers demonstrating browser code live • Anyone who wants a fast Side Panel playground Official website: https://htmlcoderunner.com/