html-viewer-with-two-way-highlight

Online HTML viewer, HTML runner, HTML test tool with real-time two-way code-element highlight. Click code to highlight preview element, click element to jump back to code. Ideal for HTML beginners.

HTML Viewer with Two-Way Highlight (For Beginners)

Overview

This is a free online HTML viewer, HTML runner, HTML test and HTML preview tool built for HTML beginners. The core feature is real-time two-way code-element highlighting, which helps learners understand the relationship between code and rendered UI quickly and intuitively.

Key Features

  • Two-way highlight: Click code to highlight the corresponding element in the preview. Click any element to jump to its source code.
  • Instant HTML preview & run: Paste HTML code and see the result immediately as a real HTML runner.
  • Simple & clean UI: No ads, no login, no installation.
  • Lightweight & fast: Pure static website, works on any browser.

Ideal For

  • HTML beginners learning tags and layout
  • Quick HTML test and debugging
  • Teaching HTML code-structure relationships
  • Online HTML preview without local environment

How to Use

  1. Open https://html-viewer.org
  2. Paste or type your HTML code in the editor
  3. The preview shows instantly as an HTML previewer
  4. Click code on the left → element highlights on the right
  5. Click element on the right → code highlights on the left

Example

<!DOCTYPE html>
<html>
<head>
  <title>Demo</title>
</head>
<body>
  <h1>Hello HTML</h1>
  <div>This box will highlight when clicked</div>
</body>
</html>