HTML Beautifier

Format and indent HTML code with configurable tag indentation, attribute wrapping, and void tag handling.

Tested tool guide Tested browser tools Checked August 16, 2026

What HTML Beautifier does, with a checked example

HTML Beautifier converts compact or inconsistently spaced HTML into a consistently indented source representation. It follows element nesting, applies the selected tag indentation, wraps attributes according to the chosen setting, and formats void elements such as br and img using the requested style. The important surprise is that readable output is not necessarily correct HTML. Beautification can expose suspicious nesting, but it does not establish that elements, attributes, accessibility relationships, or document structure conform to HTML requirements.

Worked example

A concrete input and expected output from the current implementation.

Input

<main><section></section></main>

Expected output

<main>
  <section></section>
</main>

With two-space tag indentation selected, section is placed one level inside main. The empty section has no child content requiring another indented line, so its start and end tags remain together.

How the result is produced

Element nesting

Start and end tags determine the visual nesting applied to the source. With tag indentation enabled, a child element receives one more indentation level than its parent, while sibling elements align. Comments, text, and document declarations remain part of the formatted markup. The resulting hierarchy is easier to scan, but indentation alone does not establish whether that hierarchy is valid HTML.

Attributes and void tags

Attribute wrapping changes the layout inside start tags: attributes can remain on one line or continue on indented lines according to the selected option. Void-tag handling applies to HTML elements that cannot have end tags, including br, img, input, link, and meta. In HTML, the slash in <br /> does not give br a closing tag or change it into a paired element.

Good uses

Expand a compact HTML fragment before reviewing its parent-child structure and closing tags.
Normalize indentation in a deeply nested navigation menu, form, table, or page template before a code review.
Wrap a long start tag so class, data-*, aria-*, and other attributes can be compared line by line.

Limits and checks

Beautified output is not a validation result; malformed structure or invalid attribute values can remain.
Inserted indentation and line breaks can affect visible spacing in inline or whitespace-sensitive content, so test the rendered page.
Template directives, JSX expressions, and server-side delimiters are not ordinary HTML and may not format as intended.

Common questions

Does beautifying HTML also validate or repair it?

No. A readable result is not a conformance report and does not prove that elements, attributes, IDs, URLs, or accessibility relationships are valid. Formatting may make an unmatched or unexpectedly nested tag easier to spot, but that is only a review aid. Use an HTML validator and browser testing when correctness, rather than source layout, is the question.

What does void tag handling change?

It changes how tags for HTML void elements are written, within the choices offered by the formatter. Those elements have no end tag, so </br> is not a valid paired closing form. In HTML, <br> and <br /> represent the same br element; the slash is a source-style choice, not proof that the document follows XML syntax.

References and verification

The example and behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.