What is an HTML Formatter?
An HTML formatter (or HTML beautifier) takes poorly formatted, minified, or unindented HTML code and produces a clean, consistently indented version. This is useful when you receive API responses, view a page's source code, or work with HTML generated by tools that don't produce readable output. A formatter makes the code easier to read, debug, and maintain without changing how it renders in a browser.
How to Use the HTML Formatter
Paste your HTML into the left panel. Click "Format HTML" to beautify with your chosen indentation level. The formatted result appears on the right. Click "Minify" to remove all unnecessary whitespace for production use. Use "Copy" to copy the output to clipboard. All processing happens in your browser — no data is uploaded to any server.
How the HTML Formatter Works
The formatter uses the browser's built-in HTML parser (via DOMParser) to build a DOM tree from the input, then serializes it back to HTML with proper indentation using a recursive traversal. Block-level elements (div, p, section, header, etc.) get new lines and indentation. Inline elements (span, a, strong, em) are kept on the same line as their text content. Void elements (br, img, input, hr) are self-closed.
Benefits of Formatting HTML
- Makes deeply nested HTML readable for debugging and review
- Consistent indentation makes code structure immediately visible
- Minification reduces HTML file size by 10–30% for faster page loads
- 100% client-side — your code stays private in your browser
- Useful for cleaning up CMS-generated, email-template, or legacy HTML
Frequently Asked Questions
What is HTML beautification?
HTML beautification adds consistent indentation and line breaks to make code readable. It does not change how the HTML renders in a browser — only the raw source code structure changes.
Does formatting HTML change how it looks in a browser?
No. Browsers ignore extra whitespace between tags (except inside <pre> and <code> elements). Formatted and minified HTML render identically.
What is HTML minification?
Minification removes unnecessary whitespace and comments from HTML to reduce file size. A 100KB HTML file typically reduces 10–30%. Production websites use minification to improve page load speed and Core Web Vitals.
What is the difference between HTML and XHTML?
HTML is permissive (unclosed tags allowed, attributes without quotes). XHTML follows strict XML rules (all tags must close, attributes must be quoted). HTML5 is the current standard. XHTML was common in the early 2000s.
What is semantic HTML?
Semantic HTML uses meaningful tags like <article>, <nav>, <header>, <main>, and <section> instead of generic <div>. This improves accessibility, SEO, and code readability.
Why does my formatted HTML look different from the original?
Formatters normalize tag names to lowercase, may reorder attributes, and consolidate whitespace. The rendered output in a browser remains identical. Check <pre> and <code> blocks manually as whitespace inside them is significant.
What indentation is standard for HTML?
2 spaces (Google HTML style guide, most frontend frameworks). 4 spaces (W3C examples, some backend frameworks). Tab (some CMS templates). All are functionally equivalent — choose based on your team's style guide.
Is my HTML code safe when using this formatter?
Yes. The formatter runs entirely in your browser. No HTML is sent to any server. Safe for templates containing sensitive data, API responses, or proprietary code.