HTML Viewer

Enter your HTML code to see a live preview and test responsiveness.

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HTML Viewer
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View/Run HTML Open HTML File... Clear Input Sample HTML
Download Input HTML Copy Input HTML

About the HTML Viewer Tool

This online HTML Viewer allows you to type or paste HTML code and see it rendered live in a preview pane. It's a handy tool for quickly testing HTML snippets, viewing the structure of HTML documents, or experimenting with HTML, CSS, and embedded JavaScript. You can also preview your code in common device viewport sizes.

Simply enter your code in the editor. If "Auto-update Preview" is checked, the preview will update as you type. Otherwise, click the "View/Run HTML" button. Use the device icons to change the preview size.

How to Use This Tool

  • Enter your HTML code (including any CSS within <style> tags or JavaScript within <script> tags) into the input editor.
  • Alternatively, click "Open HTML File..." to load an HTML or text file from your computer.
  • The preview pane below the input editor will render your HTML code. The "Auto-update Preview" option controls if the rendering happens as you type or only when you click the "View/Run HTML" button.
  • Click the Mobile, Tablet, or Desktop icons to resize the preview pane to simulate common device widths.
  • Use the "Sample HTML" button to load a demonstration snippet.
  • "Clear Input" will erase the content from the editor and the preview.
  • "Copy Input HTML" and "Download Input HTML" allow you to copy or save the HTML code you've entered.

All rendering is done client-side in your browser within an iframe. The `sandbox` attribute is used on the iframe for basic security, allowing scripts and forms but restricting some other capabilities.

Frequently Asked Questions

What can I use the HTML Viewer for?

You can use it to quickly test HTML, CSS, and JavaScript snippets, preview the layout of a webpage section, check how different browsers might render simple HTML (by observing the iframe), test responsiveness with the viewport size buttons, or for educational purposes to see HTML code in action.

Does the viewer execute JavaScript?

Yes, JavaScript within <script> tags in your input HTML will be executed within the preview iframe. The iframe is sandboxed with `allow-scripts` and `allow-same-origin` among others, but always be cautious when pasting code from untrusted sources.

Can I view external CSS or JavaScript files?

If your HTML code links to external CSS or JavaScript files (e.g., using <link href="styles.css"> or <script src="script.js"></script>), the browser will attempt to load them. However, this is subject to CORS (Cross-Origin Resource Sharing) policies. If the external resources are on a different domain that doesn't allow cross-origin requests, they might not load in the preview.

How are the responsive viewport sizes determined?

The tool uses common preset widths for mobile (e.g., 375px), tablet (e.g., 768px), and desktop (100% width of the preview area). The height is also adjusted to typical device aspect ratios for mobile and tablet, while desktop view maintains a fixed or larger height for better viewing.

Is my HTML code saved on your server?

No. All operations, including rendering your HTML, are performed client-side within your browser. Your code is not sent to or stored on our servers.

Is this HTML Viewer tool free?

Yes, this online HTML Viewer is completely free to use.

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