HTML Formatter Online: Beautify HTML Code in Your Browser

How to Format HTML Online

An HTML formatter makes nested markup easier to scan by placing opening and closing tags on clear lines and using consistent indentation for block elements. You can use it for a single component, a copied example, or a complete HTML document. Formatting happens only after you choose the action, so editing the input does not unexpectedly replace the output.

1. Paste source code into the HTML input. The input counter shows its current line and character count.
2. Choose two spaces, four spaces, or tabs for nested block elements.
3. Select Format HTML and review the result alongside the source.
4. Copy the formatted code or download it as an HTML file. Keep the original until you have checked the output in your project.

For example, a compact snippet such as <main><h1>Example</h1><p>A short page.</p></main> becomes a readable block with the heading and paragraph nested under main. The formatter is intended to make structure visible, not to invent missing page content.

Format a Snippet or a Full HTML Document

A small fragment is useful when checking one element or copied example. A full document is useful when you need to locate its head, metadata, body sections, or script and style blocks. Both can be pasted into the same field; no project folder or installation is required.

When you format a partial snippet, the tool leaves it as a fragment rather than adding a doctype, html, head, or body wrapper. This makes it easier to reuse a component without having the formatter add document-level tags you did not provide.

Copy or Download the Formatted Result

The result remains in a read-only output field so it cannot be edited accidentally while you compare it with the input. Copy output places the formatted text on the clipboard after a click. Download HTML saves that same text in a local file named formatted.html. Neither action changes a source file already on your computer.

What This HTML Formatter Changes

This HTML formatter is a source layout tool. It reads tag boundaries, comments, and nested block elements, then adds line breaks and the selected indentation where the structure allows it. It does not rename classes, reorder attributes, rewrite URLs, minify assets, or run JavaScript. Attribute text and inline content are copied from the input.

Whitespace-only separators between nested block elements are treated as layout. In contrast, text between inline elements is kept so that phrases such as Hello <strong>there</strong>! do not become joined together. The formatter also keeps the contents of pre, script, style, and textarea blocks together instead of indenting their internal text as HTML.

Choose Two Spaces, Four Spaces, or Tabs

Two spaces keep deeply nested markup compact and are common in front-end examples. Four spaces make each nesting level more visible in a wide editor. Tabs let a project use the display width configured by its local editor. Indentation is a team style choice; matching the surrounding repository is usually more useful than changing a whole file just for visual preference.

The setting affects indentation inserted before nested block elements. It does not convert whitespace inside text, code samples, scripts, styles, or preformatted content. If a project uses a formatter configuration or lint rule, follow that project setting when you move the result back into its source tree.

Malformed HTML and Browser Recovery

This lightweight formatter arranges tags that it can read; it is not an HTML parser conformance checker. It does not automatically repair every missing closing tag, validate attributes, or infer whether an element is allowed in its parent. If an opening tag is missing, the output may remain incomplete. Review the structure before publishing or replacing a production file.

Formatting may add whitespace around block elements. In ordinary document layout, that whitespace is usually collapsed by the browser, but text-sensitive contexts can behave differently. Mixed text and block markup is kept together where adding indentation could change the text sequence. Check the rendered result when whitespace is meaningful, especially around inline content and templates.

HTML Formatter vs. Compiler vs. Validator

These tools answer different questions. Choose the one that matches the next step in your work:

If your next question is “How does this page render?”, continue in the online HTML compiler. Use the CSS formatter to beautify or minify style rules, or the JSON formatter for structured API data. If you need to check document conformance, the W3C Nu Html Checker is a separate validation service. Formatting alone cannot confirm that a document is valid or that a script behaves as intended.

Privacy, Limits, and When to Use Another Formatter

The formatting operation runs in this page with local JavaScript string processing. The source text is not posted to an application server, and the tool does not evaluate input scripts. Copying output accesses the clipboard only after you press the copy button. The page does not store your input in an account or create a share link.

Use a project formatter when you need repeatable rules across a repository, automated formatting on save, support for JSX or template syntax, or a team configuration checked into source control. This page accepts HTML markup; it is not intended to parse JSX, Vue templates, server-side template expressions, XML, or every custom component language.

For unusually large files, a local editor can provide more precise source maps, project context, and safer change review. This page accepts up to 250,000 characters. If your browser slows down, split the file into relevant sections or work in your project editor instead.

For browser parsing behavior, see the MDN DOMParser documentation and the WHATWG HTML parsing specification. Those references describe browser parsing; this formatter's simpler text-based layout rules do not claim full standard parsing or validation.