HTML Formatter

An HTML formatter, also called an HTML beautifier, adds consistent indentation and line breaks to HTML markup so nested elements, attributes, comments, void elements, and document structure are easier to read, review, and maintain.

Paste HTML into the input panel or open a local .html file, choose your indentation style and optional settings, then click Format HTML or enable Live mode. The formatted output, heading outline, and element statistics update instantly in your browser with no server involved.

Yes. The Indent selector supports 2 spaces, 3 spaces, 4 spaces, and tabs. An Initial indent level option also lets you embed a formatted fragment at the correct nesting depth for its destination context.

Live mode re-formats the HTML input automatically as you type, with a short debounce delay to avoid interrupting fast input. Turn it on when you want immediate feedback while editing. Turn it off when processing large documents to avoid intermediate reflows.

Yes. The Preserve raw-text blocks option is enabled by default and keeps the content of pre, textarea, script, and style elements exactly as written. Disabling it normalises whitespace inside those elements, which can alter code indentation and user-visible text.

Three modes are available. Preserve on one line keeps all attributes on the opening tag. Wrap long attributes moves them to separate lines when the combined attribute string exceeds 80 characters. One attribute per line always places each attribute on its own indented line, which is useful for templates with many data attributes.

Yes. Standard HTML5 void elements including br, img, input, meta, link, hr, source, embed, track, and wbr are emitted without closing tags. The formatter does not add spurious closing tags or break void element layout.

Yes. After formatting, the Document Outline panel lists every H1 through H6 heading with colour-coded level badges and nesting offsets. This is useful for reviewing document accessibility structure and heading hierarchy before publishing.

The Statistics panel reports input bytes, output bytes, element count, maximum nesting depth, comment count, and void element count. These help you understand markup complexity and track formatting expansion across different indentation settings.

No. Formatting changes whitespace and presentation for readability. Validation checks standards conformance, required attributes, element relationships, nesting rules, and errors. Use a dedicated HTML validator when you need diagnostics rather than a beautified view.

No. Formatting expands structure with indentation and line breaks for human readability. Minification removes non-essential whitespace and comments to reduce file size for delivery. Use HTML Formatter for code review and HTML Minifier for production optimisation.

Yes. The browser DOMParser accepts fragments and full documents. Browsers may silently repair unclosed tags or normalize fragment structure during parsing, so review the output when working with intentionally incomplete markup, server-side templates, or custom elements.

Yes. Open file reads a .html or .htm file using the browser FileReader API, formats it in memory, and never sends the content to any server. You can also paste clipboard content directly from other applications.

Yes. Copy formatted places the result on the clipboard and Download .html saves a formatted.html file locally. No account, login, or server-side storage is required for either action.

No. Attribute order and quote style are preserved as the browser DOM parses them. The formatter focuses on indentation, nesting, line breaks, and optional wrapping rather than aggressive source rewriting or normalisation of attribute syntax.

When Final newline is enabled, the formatted output always ends with a single newline character. This is the conventional Unix behaviour for text files and avoids no-newline-at-end-of-file warnings in diff tools, Git, and linters.

Yes. Email HTML benefits from clean indentation before review because email clients apply their own rendering rules. Format the template source to review nesting and inline styles. Be aware that some email clients strip comments, so the Keep HTML comments toggle is useful for before-and-after comparison.

The formatter is completely free with no account required. All formatting runs locally in your browser using the native DOMParser API. No HTML content is uploaded, sent to a server, stored in localStorage or sessionStorage, or retained after you close the tab.

The Formatter focuses on structure: consistent indentation and nesting for source you are actively editing. The Beautifier focuses on recovery: turning minified or single-line HTML back into readable code. The output style is similar — pick the page that matches where your HTML came from.