What is HTML Live Preview?

HTML Live Preview is an interactive code playground that lets you write HTML, CSS, and JavaScript and see the results instantly. Think of it as a lightweight CodePen right in your browser — no sign-up required.

Whether you're a beginner learning web development or an experienced developer prototyping a quick idea, this tool gives you a fast feedback loop without setting up a local environment.

Perfect for: Quick prototyping, learning web development, testing code snippets, and sharing live examples — all without any setup or installation.

Key Highlights

Three-Tab Editor

Separate tabs for HTML, CSS, and JavaScript with full syntax highlighting powered by CodeMirror for a professional coding experience.

Instant Preview

Your code renders in a sandboxed iframe as you type, with intelligent debouncing to keep performance smooth.

Built-in Console

View console.log, warn, error, and info output without opening browser DevTools — debug right in the interface.

Download Your Work

Export a complete, standalone HTML file with your CSS and JS embedded inline — ready to use anywhere.

How to Use

Writing Code

Select a Tab

Choose between HTML, CSS, or JS tabs at the top of the editor panel to start coding in your preferred language.

Type Your Code

Write your code in the editor. The preview panel on the right updates automatically after a brief pause, giving you instant visual feedback.

Switch and Build

Move between tabs to build your HTML structure, style it with CSS, and add interactivity with JavaScript — all in one seamless workflow.

Using Templates

Click the Templates button in the toolbar to pick a starter template and jumpstart your project. Choose from:

Blank

Start from an empty slate with no pre-written code — perfect for building from scratch.

Hello World

A basic page with a button and click counter to demonstrate HTML, CSS, and JavaScript interaction.

Flexbox Layout

A responsive card grid using Flexbox — learn modern CSS layout techniques.

CSS Animation

A loading animation with keyframes demonstrating smooth CSS transitions and effects.

Note: Selecting a template replaces the current code in all three editors. Make sure to download your work first if you want to save it.

Adjusting the Layout

Resize — Drag the handle between the editor and preview to make either panel larger or smaller based on your needs
Toggle layout — Click the layout button to switch between side-by-side (horizontal) and stacked (vertical) views
Fullscreen preview — Click the expand button to view the preview in fullscreen. Press Escape or click the close button to return

Using the Console

Click the Console button (terminal icon) to open the console panel. Any console.log(), console.warn(), console.error(), or console.info() calls in your JavaScript will appear here with appropriate icons and styling.

Without Console

Traditional Debugging

Open browser DevTools
Navigate to Console tab
Switch between windows
Lose focus on code

With Built-in Console

Streamlined Workflow

One-click console access
View output inline
Stay in the editor
Clear with trash icon

Downloading Your Code

Click the Download button to save your work as a single preview.html file. The exported file includes your HTML in the body, CSS in a <style> tag, and JavaScript in a <script> tag — ready to open in any browser.

Pro tip: The downloaded file is completely self-contained with no external dependencies. You can share it, host it, or use it as a starting point for larger projects.

Features

Code Editor with Syntax Highlighting

The editor is powered by CodeMirror and provides syntax highlighting for HTML, CSS, and JavaScript. It also includes auto-closing brackets and tags, bracket matching, and proper indentation with soft tabs.

Syntax Highlighting

Color-coded syntax for HTML, CSS, and JavaScript makes code easier to read and understand.

Auto-Closing

Automatically closes brackets, quotes, and HTML tags as you type for faster coding.

Smart Indentation

Proper indentation with soft tabs keeps your code clean and properly formatted.

Live Preview

Your code runs inside a sandboxed iframe that updates automatically as you type. The preview supports full HTML documents with embedded CSS and JavaScript, giving you an accurate representation of how your code will look in a real browser.

Sandboxed iframe for security
Automatic updates as you type
Full HTML document support
Embedded CSS and JavaScript
Real browser rendering

Built-in Console

No need to open your browser's DevTools. The built-in console panel captures all console output from your JavaScript — including log, warn, error, and info messages. A badge on the console button shows you how many messages have been logged.

Console Method	Icon	Use Case
`console.log()`	Info	General debugging output
`console.warn()`	Warning	Potential issues or deprecations
`console.error()`	Error	Runtime errors and exceptions
`console.info()`	Info	Informational messages

Resizable Panels

Drag the divider between the editor and preview to allocate more space to whichever panel you need. The resizer supports both horizontal and vertical layouts and clamps between 20% and 80% to keep both panels usable.

Minimum Editor Width 20%

Maximum Editor Width 80%

Layout Toggle

Switch between horizontal layout (editor left, preview right) and vertical layout (editor top, preview bottom) with a single click. The vertical layout works well on narrower screens or when you want a wider preview.

Horizontal

Side-by-side layout for wide screens

Vertical

Stacked layout for narrow screens

Fullscreen Preview

Expand the preview to fill your entire screen for a distraction-free view of your work. Exit by pressing Escape or clicking the close button in the top-right corner.

Keyboard shortcut: Press Escape to quickly exit fullscreen mode and return to the editor.

HTML Export

Download your creation as a standalone HTML file. The exported document includes proper doctype, meta tags, and your CSS and JavaScript embedded inline — no external dependencies needed.

Exported HTML Structure

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" c>
    <title>HTML Live Preview</title>
    <style>
        /* Your CSS here */
    </style>
</head>
<body>
    <!-- Your HTML here -->
    
    <script>
        // Your JavaScript here
    </script>
</body>
</html>

Starter Templates

Get started quickly with built-in templates that demonstrate common patterns: a Hello World page, a Flexbox card layout, and a CSS keyframe animation. Each template populates all three editor tabs with working example code.

Pre-written, working code examples
Learn by examining real implementations
Modify templates to fit your needs
Understand best practices through examples

Frequently Asked Questions

Is my code sent to a server?

No. All code editing, preview rendering, and console output happen entirely in your browser. Nothing is uploaded or stored on any server.

Privacy guaranteed: Your code stays on your device. This tool works completely offline once loaded.

Can I use external libraries like Bootstrap or jQuery?

Yes. Add a <link> or <script> tag in the HTML tab pointing to a CDN URL, and the library will load inside the preview iframe.

Example: Loading Bootstrap from CDN

<link href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css" rel="stylesheet">
<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/js/bootstrap.bundle.min.js"></script>

Why does my JavaScript not work?

The preview runs in a sandboxed iframe with allow-scripts and allow-modals permissions. Most JavaScript works normally, but some browser APIs that require additional permissions may be restricted.

Check the built-in console for error messages
Verify your syntax is correct
Ensure external libraries are loaded properly
Some APIs (clipboard, geolocation) may be restricted in sandboxed iframes

Common issue: APIs requiring user permissions (like clipboard access or geolocation) may not work in the sandboxed preview environment.

Can I save my work?

Use the Download button to export your code as a standalone HTML file. You can reopen this file in any browser or paste the code back into the editor later.

Click Download to save as preview.html
File includes all HTML, CSS, and JavaScript
No external dependencies required
Open in any browser or text editor
Copy code back to editor anytime

Does the editor support mobile devices?

Yes. On smaller screens, the layout automatically switches to a vertical stacked view. The resizer supports touch events for drag-to-resize on mobile and tablet devices.

Device Type	Layout	Features
Desktop	Horizontal (default)	Full features, drag-to-resize
Tablet	Horizontal or Vertical	Touch-enabled resizing
Mobile	Vertical (auto)	Touch-optimized interface

What is the console panel for?

The console panel captures output from console.log(), console.warn(), console.error(), and console.info() in your JavaScript code. It also catches runtime errors and unhandled promise rejections.

This lets you debug without opening your browser's developer tools, keeping your workflow streamlined and focused on the code.

View all console output in one place
Color-coded message types (log, warn, error, info)
Badge counter shows total messages
Clear all messages with trash icon
Catches runtime errors automatically