What is an HTML formatter?
An HTML formatter (also called an HTML beautifier) takes raw markup and rewrites it with consistent indentation and line breaks so the nesting structure is visible at a glance. HTML is the foundation of every web page, email template, and server-rendered document. Developers inspect it in DevTools, designers tweak templates, and marketers edit CMS output. Yet the HTML that tools generate is often compressed — tags crammed together on single lines, inconsistent spacing, and deeply nested elements with no visual hierarchy.
This tool solves that instantly. Paste any HTML — minified, copied from a browser, or hand-edited — and get cleanly indented output. Choose between 2-space, 4-space, or tab indentation, copy the result, or download it as a .html file. Processing happens entirely in your browser using the industry-standard js-beautify library.
How to use the HTML formatter
- Paste your HTML into the input panel on the left. Click Load sample to try a small page structure with header, main content, and a list.
- Choose an indentation style from the dropdown.
- Click Format to beautify the markup. Errors appear above the button if the input cannot be processed.
- Review the output in the right panel. Opening and closing tags align vertically so you can spot missing or mismatched elements quickly.
- Copy or download the formatted HTML for use in your editor, ticket, or documentation.
Example
Before: minified markup
<div class="card"><h2>Title</h2><p>Body text with <a href="/">a link</a>.</p><ul><li>One</li><li>Two</li></ul></div>After: formatted with 2-space indentation
<div class="card">
<h2>Title</h2>
<p>Body text with <a href="/">a link</a>.</p>
<ul>
<li>One</li>
<li>Two</li>
</ul>
</div>The nested list and anchor tag are immediately visible. When debugging a layout issue or reviewing a pull request, that structure saves time.
Why formatting HTML matters
Readable HTML accelerates debugging. When a component renders incorrectly, the first step is understanding the DOM structure. A formatted tree makes it obvious which wrapper div is missing a closing tag, which section is nested too deeply, or where a CMS injected unexpected markup. Code reviews of template changes produce clearer diffs when both sides use consistent indentation.
Email developers benefit especially. HTML emails rely on table-based layouts with inline styles, and a single missing </td> can break rendering in Outlook. Formatting the template before testing catches structural problems faster than scrolling through a one-line blob.
Common scenarios
- DevTools copy— Browser inspector "Copy outer HTML" often returns minified output. Format it before sharing.
- Server-rendered pages — Framework output from React, Vue, or Angular SSR can be hard to read without beautification.
- Legacy templates — Old JSP, PHP, or ASP files benefit from consistent formatting before refactoring.
- Learning — Beginners understand document structure faster when tags are visually nested.
Related tools
- Format the stylesheet with the CSS Formatter.
- Format inline or external scripts with the JavaScript Formatter.
- For strict XML-style documents, try the XML Formatter or XML Validator.