Frontend

Online HTML Editor

The online HTML editor gives you a fast browser sandbox for testing complete HTML documents, CSS styles and small JavaScript interactions. It is useful for layout experiments, teaching examples, form prototypes and quick bug reproduction because the preview runs in an isolated iframe. The page includes practical examples and web-specific FAQs rather than generic compiler copy.

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Online compiler

HTML workspace

File: index.htmlLive preview

HTML editor

File: index.html

Live preview

Output

Success

Ready.

Live preview renders the HTML document in an isolated iframe.

How to use this HTML editor

Open the HTML starter code or choose another example from the dropdown.
Edit the code and press Run Preview to refresh the isolated browser preview.
Review stdout, errors, compile output or table results in the output panel.
Copy the code or download it as a .html file when the result looks right.

HTML features

Isolated iframe preview
Single-file HTML workflow
Responsive preview sizes
Copy and download .html files
Interactive DOM examples
No server execution required

Common use cases

Prototype landing sections
Teach HTML structure
Test CSS quickly
Reproduce browser bugs

HTML example code

A complete HTML page with CSS and a button.

<!doctype html>
<html lang="en">
  <head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1" />
    <title>Anku HTML Preview</title>
    <style>
      body { font-family: system-ui, sans-serif; margin: 0; padding: 32px; background: #f8fbff; color: #0f172a; }
      main { max-width: 680px; margin: auto; background: white; border: 1px solid #dbeafe; border-radius: 16px; padding: 28px; }
      button { border: 0; border-radius: 999px; background: #2563eb; color: white; padding: 10px 16px; font-weight: 700; }
    </style>
  </head>
  <body>
    <main>
      <h1>HTML live preview</h1>
      <p>Edit this document and run it to refresh the isolated preview.</p>
      <button onclick="document.querySelector('#status').textContent = 'Button clicked at ' + new Date().toLocaleTimeString()">Try interaction</button>
      <p id="status">Waiting for a click.</p>
    </main>
  </body>
</html>

Sample output

Live preview renders the HTML document in an isolated iframe.

Common HTML errors

Styles not applying: Check selector spelling and make sure your style tag is inside the document.
Script runs too early: Place scripts near the end of body or wait for DOMContentLoaded.
Preview looks different on mobile: Keep the viewport meta tag and test the mobile preview size.

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Frequently Asked Questions

Does the HTML editor run server code?

No. It previews client-side HTML, CSS and JavaScript inside an isolated iframe.

Can I test CSS and JavaScript together?

Yes. Keep style and script tags in the same HTML document, or use the examples as a starting point.

Is the preview automatic?

Use Run Code to refresh the preview. This keeps edits predictable while you are experimenting.

Can I download the page?

Yes. Download saves the current document as an .html file.

When should I use the React tool instead?

Use React when you want component state, JSX and React-specific examples rather than plain browser APIs.