代码游乐场

About Code Playground

Code Playground is a free online live editor for HTML, CSS, and JavaScript. It provides an instant preview of your code as you type, making it perfect for rapid prototyping, learning web development, and testing code snippets. All processing happens entirely in your browser — no code is sent to any server, ensuring complete privacy and security. Whether you are a beginner learning the basics of web development or an experienced developer testing a quick idea, this tool gives you a sandbox environment with zero setup required.

Features

• Live HTML/CSS/JS editor with instant preview — see changes as you type
• Three separate code panels for HTML, CSS, and JavaScript with syntax-aware editing
• Auto-run mode — preview updates automatically when you stop typing
• Manual run button for precise control over when to execute code
• Horizontal and vertical layout modes — switch editor orientation to fit your workflow
• Built-in console output — view JavaScript console.log messages directly in the tool
• Download your complete HTML file with one click — save your work locally
• Reset and example buttons — start fresh or load a demo to get started quickly
• Responsive sandboxed iframe preview — your code runs safely in an isolated environment
• 100% client-side — your code never leaves your browser or gets uploaded to any server

How to Use

1. Open the HTML tab and write your HTML markup in the editor panel
2. Switch to the CSS tab and add your styles — the preview updates automatically if Auto Run is enabled
3. Open the JavaScript tab and write your JS code — click Run or wait for auto-run to see the result
4. View the live preview in the right panel — it reflects all your HTML, CSS, and JS combined
5. Check the console output below the preview for any JavaScript logs or errors
6. Click Download HTML to save your complete code as a single .html file

Frequently Asked Questions

Is this Code Playground free to use?

Yes, the Code Playground is completely free with no usage limits, no registration required, and no ads. You can write, test, and preview code as much as you need. All processing happens locally in your browser for complete privacy.

Is my code kept private?

Absolutely. All code execution and rendering happens entirely in your browser. No code is sent to any server, uploaded to the cloud, or stored externally. Your code remains on your device only.

Can I use external libraries like React or Bootstrap?

Currently, the playground runs your code in a sandboxed iframe without external CDN access. For testing frameworks with external dependencies, you can include them via inline script tags or use a dedicated online playground like CodePen or JSFiddle.

Why is my JavaScript not running?

Make sure Auto Run is enabled (checkbox is checked), or click the Run button manually. Also check the console output panel for any JavaScript errors. Common issues include syntax errors, undefined variables, or trying to access the DOM before the page loads.

Can I save my code and share it with others?

You can download your code as a single .html file using the Download button. To share with others, you can send them the file or copy-paste the code into a code-sharing platform like GitHub Gist, CodePen, or JSFiddle.

What browsers are supported?

The Code Playground works on all modern browsers including Chrome, Firefox, Safari, and Edge. It uses standard Web APIs that are supported across all modern desktop and mobile browsers.

Common Use Cases

• Learning HTML, CSS, and JavaScript — experiment with code and see results instantly
• Rapid prototyping — test UI ideas and component designs before building in your project
• Debugging snippets — isolate and fix small pieces of code without affecting your main project
• Teaching and demos — demonstrate web concepts to students or team members with live examples
• Interview preparation — practice coding challenges and CSS layout problems in a clean environment
• Testing responsive designs — resize the preview panel to see how your code looks on different screen sizes

Related Tools

• HTML Formatter — beautify and clean your HTML code
• CSS Formatter — format and organize your CSS stylesheets
• JS Formatter — beautify and minify JavaScript code
• JSON Formatter — validate and format JSON data
• Color Converter — convert between RGB, Hex, HSL, and CMYK
• CSS Flexbox Playground — learn and experiment with CSS Flexbox layouts