HTML Beautify — Online HTML Formatter and Pretty-Printer
🔒 Runs in your browser — nothing is sent to a serverHTML formatter that turns any compact, minified or hand-written HTML into a clean, indented document. Paste a Tailwind component, a server-rendered page, an email template or any HTML blob, and this HTML beautifier parses it through the browser's native `DOMParser`, then pretty-prints the tree with 2 or 4 spaces or tab indentation. `<pre>`, `<textarea>`, `<script>` and `<style>` content is preserved verbatim; inline tags like `<a>`, `<span>` and `<strong>` stay on the same line as their parent text; void tags (`<br>`, `<img>`, `<input>`) skip the closing tag. Everything runs 100% inside your browser; your input never leaves your device.
Content of <pre>, <textarea>, <script> and <style> is preserved verbatim.
When to use an HTML beautifier
You reach for an HTML beautifier any time a one-line HTML payload arrives unreadable: debugging the response of an SSR endpoint, peeking inside a marketing email pulled from your ESP, untangling a Tailwind-laden component you copied from a template, comparing two server-rendered pages with `diff`, walking through an admin export, or preparing an HTML snippet for inclusion in documentation. The pretty-printed form is what most readers and tools expect, and what Prettier produces. Running the format in a browser-local tool keeps the payload off remote servers — important when the HTML carries tokens, internal URLs or PII.
How HTML beautifying works under the hood
HTML beautifying is a three-step pipeline. First the input is scanned for the DOCTYPE — it lives outside the document tree, so it is pulled aside before parsing. Second the input is fed through `new DOMParser().parseFromString(input, "text/html")`; the HTML parser is lenient, so almost any input parses. Third a recursive tree walker re-emits every element: inline tags stay inline with parent text, block tags get their own line, `<pre>`/`<textarea>`/`<script>`/`<style>` are preserved verbatim, boolean attributes are normalised to bare names, and long opening tags wrap onto multiple lines. Conditional comments are always kept; ordinary comments are kept by default. The whole pipeline runs inside the browser, so a multi-megabyte HTML document beautifies in milliseconds without leaving your tab.
Examples
<!DOCTYPE html><html lang="en"><head><meta charset="UTF-8"><title>Hello</title></head><body><h1>Atlas</h1><p>Welcome to <strong>free-converter.online</strong>.</p></body></html><!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Hello</title>
</head>
<body>
<h1>Atlas</h1>
<p>Welcome to <strong>free-converter.online</strong>.</p>
</body>
</html><section class="card"><h2>Products</h2><ul><li>Atlas <em>(new)</em></li><li>Vesper</li></ul></section><section class="card">
<h2>Products</h2>
<ul>
<li>Atlas <em>(new)</em></li>
<li>Vesper</li>
</ul>
</section><article data-tool="html beautify"><h1>html formatter tool</h1><p>Beautify HTML online inside your browser.</p></article><article data-tool="html beautify">
<h1>html formatter tool</h1>
<p>Beautify HTML online inside your browser.</p>
</article><div><pre> if (a < b) {
x = 1;
}</pre><script>const y = 2;</script></div><div>
<pre> if (a < b) {
x = 1;
}</pre>
<script>const y = 2;</script>
</div>