HTML Prettifier

THE PRACTICAL GUIDE · NORMANDIN SYSTEMS

Get more from HTML Prettifier

HTML Prettifier adds a readable layout to markup so nested elements and document sections are easier to follow. It is useful when inspecting a single-line export or reviewing copied markup before editing. Readable indentation can reveal structure, but it does not validate accessibility, repair every malformed document, or explain the CSS and JavaScript that act on the elements. Code transformations are most useful when you know the language and the surrounding context of the snippet. Work from a saved copy and start with a small, valid example that demonstrates the behavior you need. Formatting, encoding, and generation do not establish that a program is correct. Review the output as source code, keep meaningful comments when appropriate, and test the result in the same environment that will eventually interpret it. This makes subtle changes much easier to spot.

Guide updated October 13, 2026

How to use this tool

1. Paste a small, representative snippet and keep a copy of the input. Include the punctuation and delimiters needed to make the example meaningful.
2. Paste the document or fragment and inspect the formatted nesting, preserving a copy of the original text.
3. Review the example below and compare its expected behavior with a small sample of your own input before continuing.
4. Copy the result into a scratch file and verify it with the intended parser, editor, or test environment before replacing the original code.

SEE IT IN PRACTICE

A worked example

<section><h2>Title</h2><p>Text</p></section>

A section with clearly indented heading and paragraph elements

The formatting makes the parent-child relationship visible without intentionally changing the content or element names.

Indentation reveals the parsed shape

A nested layout is easier to inspect when the source visually groups related elements. Use the formatted result to identify parent-child relationships, mismatched expectations, and large repeated blocks. However, browsers have error-recovery behavior for malformed markup, so the visual document tree may differ from the indentation you expected. When structure matters, inspect the browser's actual DOM alongside the formatted text rather than treating the formatter as a complete validator.

Rendering is the final whitespace check

Formatting adds or changes whitespace around markup, and that deserves attention in inline text, preformatted regions, and embedded code. A paragraph with links or emphasized words can display unwanted spacing even when its indentation looks attractive. Compare a rendered sample and preserve the source before a broad formatting pass. If the HTML belongs to a template system, also verify that delimiters and directives remain intact. The benefit should be a clearer source representation without accidental changes to content or template behavior.

When this tool is useful

• Review compressed page markup
• Understand nested HTML structure
• Prepare a fragment for a collaborative code review

Tips for a better result

• Compare text content, embedded code, and element order, then render a representative page using the formatted result.
• Separate a syntax check from a behavior check. A snippet can parse successfully while producing the wrong value, selecting the wrong element, or changing an important edge case.
• Keep the source and the settings used for this result together. That makes a later comparison or correction easier, especially when another person needs to reproduce the same outcome.

Frequently asked questions