ModernCalcs

HTML Beautifier

Indent
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>
      My Page
    </title>
    <link rel="stylesheet" href="styles.css">
  </head>
  <body>
    <header>
      <nav>
        <ul>
          <li>
            <a href="/">
            Home
            </a>
          </li>
          <li>
            <a href="/about">
            About
            </a>
          </li>
          <li>
            <a href="/contact">
            Contact
            </a>
          </li>
        </ul>
      </nav>
    </header>
    <main>
      <section class="hero">
        <h1>
          Welcome
        </h1>
        <p>
          This is the hero section with
          <strong>
          bold text
          </strong>
          and a
          <a href="#">
          link
          </a>
          .
        </p>
        <button type="button">
          Get Started
          </button>
        </section>
      </main>
      <footer>
        <p>
          &copy; 2025 My Company
        </p>
      </footer>
    </body>
  </html>

Block elements (div, p, section, etc.) each get their own indented line. Inline elements (a, span, strong, etc.) stay on the same line as surrounding text.

HTML Beautifier: Expand Minified HTML Into Readable Markup

Minified HTML saves bytes but makes the structure invisible. This beautifier tokenizes HTML into its component tags and text nodes, then lays them out with indentation based on block nesting — making it easy to see the document structure, find a specific element, or review a template before editing.

Formula
// Input: minified <html><head><title>Page</title></head><body><main><h1>Hello</h1><p>World</p></main></body></html> // Output: indented <html> <head> <title>Page</title> </head> <body> <main> <h1>Hello</h1> <p>World</p> </main> </body> </html>

Block elements get their own indented line. Inline elements (a, span, strong, etc.) stay on the same line as their surrounding text.

Block vs Inline Elements

HTML elements are categorized as block-level (div, p, section, h1-h6, ul, li, nav, main, header, footer, article, form, table, tr, td) or inline (a, span, strong, em, code, img when inside text). Block elements get their own lines with increased indentation for their children. Inline elements flow within the current line.

Void Elements

Void elements (br, hr, img, input, link, meta, area, base, col, embed, param, source, track, wbr) have no children and no closing tag. They are output on their own indented line without increasing the indentation for subsequent elements.

Beautified vs Minified HTML

Beautified HTML is for human readability — editing, reviewing, and understanding template structure. For production, HTML should be minified (whitespace collapsed, comments removed) to reduce page size and improve load time. Use the HTML Minifier tool here to go the other direction.

Practical Examples

Reading a Downloaded Web Page

Browser-delivered HTML is often minified. Beautify it to understand the structure.

  • 1.Open your browser's DevTools, copy the outer HTML of the page or a component
  • 2.Paste here — even deeply minified HTML is handled
  • 3.Review the indented structure to understand element nesting and class names
  • 4.Use this to guide your own template work or understand a third-party component

Element Categories Used

  • Block elements: own line + increased indent for children
  • Inline elements: flow within surrounding text on same line
  • Void elements: own line, no child indent
  • DOCTYPE and comments: own line at current depth

Good Use Cases

  • Reading minified HTML from production web pages
  • Reviewing AI-generated HTML templates
  • Understanding a Bootstrap or Tailwind UI component's structure
  • Before editing: formatting an existing template for clarity

Frequently Asked Questions

What are block vs inline elements?

Block elements (div, p, section, h1-h6, ul, li, nav, main, header, footer, article, etc.) create line breaks before and after their content. Inline elements (a, span, strong, em, code, etc.) flow within text. The beautifier puts block elements on their own lines and keeps inline elements with their surrounding text.

What are void elements?

Void elements (br, hr, img, input, link, meta, etc.) have no children and no closing tag. They are output on their own line without adding indentation for a child block.

Does this preserve comments?

Yes. HTML comments () are output on their own line at the current indentation depth.

Will formatted HTML be larger?

Yes. Formatting adds whitespace — newlines and indentation — which increases file size. For production, the formatted HTML is not the file you serve; it is for readability only. Minify the HTML before serving to users.

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