HTML Formatter & Beautifier

Working with minified or messy HTML? Paste it into HTML Viewer Cat and instantly see the rendered output — even if the source is a single unreadable line. The syntax-highlighted editor makes it easy to read the structure, and the live preview shows you exactly what the browser sees.

Why format HTML?

Minified HTML saves bytes but is impossible to read. Copy-pasted HTML from emails, CMSes, or generated output is often a wall of text with no indentation. Formatting makes the structure visible so you can understand nesting, find unclosed tags, and debug layout issues.

How HTML Viewer Cat helps

• Syntax highlighting — tags, attributes, and values are color-coded so you can visually parse the structure even without indentation
• Live preview — see the rendered output immediately to verify the HTML does what you expect
• Edit in place — make changes directly in the editor and see the preview update in real time
• Responsive check — test the formatted output across phone, tablet, and desktop widths

Common sources of messy HTML

• Minified production builds
• HTML email templates from marketing platforms
• CMS-generated output (WordPress, Shopify, etc.)
• Copy-pasted code from browser DevTools
• Auto-generated HTML from design tools

How to use it

1. Open the editor
2. Paste your messy or minified HTML
3. The syntax highlighting makes the structure readable
4. The preview panel shows the rendered output
5. Edit the code directly to fix any issues you find