📄 HTML Formatter & Beautifier
Format, beautify, and minify HTML online. Preserves script/style content, handles void elements correctly. Free, browser-based — no uploads.
HTML Formatter is a browser-based tool that transforms cluttered or minified HTML into readable, hierarchically indented code. It parses HTML with DOMParser, indents each tag by nesting depth, and strips false closing tags from void elements (like br, img, input). Script and style block contents are preserved untouched; the same tool can also compress HTML for production delivery via the Minify mode.
What Is an HTML Formatter?
This tool formats, beautifies, and minifies HTML — the standard markup language for web pages and applications. You paste HTML code, and the tool parses it using your browser's native DOMParser, then reformats it with proper hierarchical indentation for readability or compresses it to a single line for production. Unlike other formatters, this tool preserves script and style block contents by default — it won't break your JavaScript or CSS — and correctly handles void elements (br, img, input, etc.) without adding false closing tags. All processing runs in your browser.
Format, Minify, Preserve
| Action | What It Does | Output |
|---|---|---|
| Beautify | Adds line breaks and 2-space indentation | Readable, structured HTML |
| Minify | Removes all unnecessary whitespace | Compact single-line HTML |
| Preserve | Keeps script/style block contents untouched | Safe formatting, no JS/CSS corruption |
Beautify uses 2-space indentation. Minify removes newlines and non-essential whitespace. The Preserve option (on by default) ensures inline JavaScript and CSS remain identical to the original — the formatter only adjusts the surrounding HTML structure.
Void Element Handling
HTML specifies 14 void elements that must not have closing tags:
area, base, br, col, embed, hr, img, input, link, meta, param, source, track, wbr
Many formatters that rely on DOMParser's raw output produce incorrect </br> or </input> tags. This tool post-processes the output and strips these false closing tags, ensuring spec-compliant HTML every time.
Limitations
- No HTML validation. The tool formats structure but does not validate against W3C standards. Use a dedicated validator for compliance checking.
- Fixed 2-space indent. Indentation width is not configurable.
- HTML5 parser. Uses the browser's DOMParser (HTML5 spec). Legacy or non-standard markup may be normalized during parsing.
- 1 MB input limit. Inputs exceeding 1 MB show a warning. Browser memory may limit very large documents further.
- No file upload or download. Paste only. No drag-and-drop or save-to-file support.
📋 When to Use the HTML Formatter
The HTML Formatter is essential for developers who need clean, readable HTML. Use it to inspect minified production HTML, format code snippets for documentation, clean up messy markup from WYSIWYG editors, or standardize HTML indentation before code reviews. Because all processing runs in your browser, it's safe for work-in-progress or sensitive code that shouldn't leave your machine.
⚙️ How the HTML Formatter Works
The HTML Formatter uses a parsing and formatting pipeline that runs entirely in your browser. When you paste HTML, the tool parses it with the browser's native DOMParser (HTML5 mode). Then it walks the DOM tree and serializes each node — adding 2-space indentation per nesting level for beautify mode, or removing non-essential whitespace for minify mode. Void elements like br, img, and input are recognized via a whitelist and their erroneous closing tags are stripped. Script and style block contents are preserved as-is when the preserve option is enabled. All processing is client-side JavaScript — your code never leaves your machine.
How to Use the HTML Formatter & Beautifier
- Paste your HTML — Drop any HTML into the input area, even minified or messy markup. A sample is pre-loaded.
- Choose mode — Select Beautify for readable indented output, or Minify for compressed single-line HTML.
- Toggle options — Enable or disable script/style content preservation. When on, inline JavaScript and CSS are left untouched.
- Click Format — Your HTML is beautified or minified. Void elements like br and img are handled correctly without false closing tags.
Frequently Asked Questions
Will formatting break my inline JavaScript?
Not by default. ToolStand preserves <script> and <style> block contents untouched — it only adjusts the surrounding HTML indentation. Minified JS, template literals, and regex expressions remain identical to the original. If you want inline scripts formatted too, disable the "Preserve script/style" checkbox.
Why do some formatters add </br> or </input> tags?
HTML spec defines these as "void elements" — they must not have closing tags. Many formatters use DOMParser's raw output, which can produce erroneous </br> or </input>. ToolStand recognizes all 14 void elements (area, base, br, col, embed, hr, img, input, link, meta, param, source, track, wbr) via a whitelist and strips these false closing tags.
How do I make minified HTML readable?
Paste your minified HTML into ToolStand, select "Beautify" mode, and click Format. The tool parses the structure with DOMParser and produces properly indented, readable output. You can also switch to "Minify" mode to compress HTML back for production use — all in the same tool.
What's the difference between an HTML formatter and validator?
A formatter adjusts code appearance (indentation, whitespace, readability) — it does not check structural validity. A validator checks HTML against W3C standards (missing tags, wrong nesting, invalid attributes). ToolStand's HTML Formatter is a beautifier — it formats code but does not provide a validation report. For HTML validation, use the W3C Validator.
Can it handle large HTML files (1 MB+)?
Yes. ToolStand's HTML Formatter accepts up to 1 MB of input — about 10–50× the size of a typical web page. Inputs exceeding 1 MB show a clear warning. Because all processing happens in your browser (client-side), file size is limited only by your device's memory; no data is ever sent to a server.
Cite this tool
@misc{toolstand_htmlformatter,
title = {HTML Formatter & Beautifier},
author = {{ToolStand}},
year = {2026},
url = {https://toolstand.io/tools/html-formatter/}
}Using this tool in a post or paper? Copy a ready-made reference above.
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