Use Cases

The HTML Playground is a free, browser-based sandbox for testing HTML, CSS, and JavaScript. Use it for quick experiments, debugging snippets, checking responsive layouts, and sharing a working example. Here are practical ways to get the most out of it:

Paste a Complete HTML File
Switch to "Single file" mode and paste a full .html document with inline <style> and <script> blocks to see exactly what it renders, with no manual splitting.
Separate HTML / CSS / JS Panes
Author markup, styling, and behavior in three clearly separated panes and toggle "Separated" mode to watch the assembled output update live.
Live (Debounced) Preview
Type in any editor and the preview refreshes automatically after a short debounce, so you can iterate fast without pressing a button after every edit.
View Console Output
When your JavaScript logs values or throws an error, the collapsible console panel shows log, warning, and error output plus uncaught exceptions, with a one-click clear action.
Preview at Device Width and Export
Check the mobile layout with the device-width toggle, then Copy the standalone HTML to your clipboard or Download a single self-contained .html file to share.

Frequently Asked Questions

How do I use this app?: Choose either "Separated" (edit HTML, CSS and JS in their own panes) or "Single file" (paste one complete HTML document), type or paste your code, and the preview updates automatically. Use the Run button to refresh manually, the console panel to see errors, and Copy/Download to export the result.
Can I paste a whole HTML file with CSS and JS inside?: Yes. In "Single file" mode, paste the entire HTML document including its <style> and <script> blocks and it is rendered as-is.
What happens to my code?: Your code stays in your browser. It is only rendered inside a sandboxed preview on this page and is stored locally in your browser so you can pick up where you left off. The app does not upload your code to a server.
Why does my code not run or show an error?: Open the console panel to see the exact error or warning. Common causes are JavaScript syntax errors, missing elements referenced by your code, or scripts that require a network resource. Fix the highlighted error and the preview refreshes automatically.
Can I save or share my work?: Yes. Use Copy to put the standalone HTML on your clipboard, or Download to save a single .html file you can open or share. Your code is also remembered locally between visits until you press Clear.