HTML Minifier

About this tool

HTML Minifier shrinks HTML by removing comments and collapsing whitespace. Paste a document or fragment and the minified output updates as you type, with input and output byte counts. Three options control it: Remove comments (conditional IE comments are kept), Collapse whitespace, and Preserve case — untick it to lowercase tag and attribute names. Text inside <script>, <style>, <pre> and <textarea> is skipped while collapsing, but a final cleanup still removes whitespace that sits directly before any < character, including inside those blocks. That cleanup also removes the space between a word and a following tag, so Hello <b>world</b> becomes Hello<b>world</b> and renders as Helloworld; review text-heavy output before you deploy it, or untick Collapse whitespace. The tool does not remove optional closing tags, unquote attributes, or minify inline CSS and JavaScript. Everything runs in your browser.

Why use it

• Faster Time-to-First-Byte: Every byte removed from an HTML response is processed sooner by the browser. Minified HTML reduces TTFB for uncached responses and decreases the payload the CDN edge must forward to the client.

• Comment Stripping: HTML comments like <!-- TODO: fix this --> are invisible to users but add bytes to every response. Remove comments strips them, while conditional IE comments are kept.

• Exact Byte Counts: Input and output byte counters show exactly how much the minified version saves.

• Lowercase Option: Untick Preserve case to lowercase tag and attribute names, which tidies markup exported in upper case.

• Compounds Well with Gzip: Minification and compression are complementary, not competing. Removing repetitive structural characters before gzip gives the compression algorithm more consistent patterns to work with, improving the compression ratio.

• No Build Pipeline Required: Static sites, HTML email templates, and single-file utilities can be minified here without wiring up a gulp, webpack, or Vite build step. Paste, minify, deploy.

How to use

1. Paste your HTML document or template fragment into the Input HTML box.
2. The minified output updates as you type, with Input bytes and Output bytes counters below.
3. Use the Remove comments, Collapse whitespace and Preserve case checkboxes to control the transformations.
4. Check inline text in the output: with Collapse whitespace on, spaces before tags are removed, so words next to <b>, <a> or <span> can run together.
5. Click Copy to copy the minified HTML to your clipboard.
6. Click Clear to empty both boxes and reset the counters.

When it helps

• Before uploading a static HTML file to a CDN origin or S3 bucket for a production deployment.
• When optimising HTML email templates where payload size affects deliverability and render speed in email clients.
• After generating HTML from a templating engine to strip the human-readable whitespace added for template author convenience.
• When running a Lighthouse audit that flags render-blocking HTML size as a performance opportunity.
• Before publishing a single-file utility or code pen that needs to fit within an embed or paste size limit.
• When comparing two versions of a template by first minifying both — to eliminate formatting-only diffs — before diffing for real changes.

Examples

<!-- Site header -->
<header class="site-header">
  <nav class="main-nav">
    <ul>
      <li><a href="/tools">Tools</a></li>
      <li><a href="/about">About</a></li>
    </ul>
  </nav>
</header>

<header class="site-header"><nav class="main-nav"><ul><li><a href="/tools">Tools</a></li><li><a href="/about">About</a></li></ul></nav></header>

<DIV CLASS="box">
  <!-- note -->
  <P>Text</P>
</DIV>

<div class="box"><p>Text</p></div>

<table class="data-table">
  <tr>
    <td>Alice</td>
    <td>98</td>
  </tr>
</table>

<table class="data-table"><tr><td>Alice</td><td>98</td></tr></table>

Tips

• Always test minified HTML in a browser before deploying — edge cases around inline whitespace can cause text to run together in rare layouts.
• Keep the formatted source HTML in version control and only deploy the minified output; debugging minified HTML in production DevTools is painful.
• Conditional comments (<!--[if lt IE 9]>) are kept even with Remove comments on, so legacy IE blocks survive minification.
• For HTML emails, consider leaving Collapse whitespace off — email text with inline links and bold words is especially prone to words running together.
• Combine with server-level gzip or Brotli — a 20% minification saving followed by 70% compression saving gives an overall 76% reduction in wire weight.

Frequently Asked Questions

Glossary

Optional Closing Tags

HTML5 closing tags that browsers do not require to correctly parse the document, including </li>, </p>, </td>, and </tr>. Omitting them is spec-compliant and saves bytes.

Whitespace Collapsing

Reducing sequences of spaces, tabs, and newlines between HTML elements to nothing or a single space. Safe between block elements; must be done carefully between inline elements.

Render-Blocking

HTML, CSS, or JS resources that the browser must fully download and process before it can paint the first pixel of the page. Smaller HTML reduces the time spent in this blocking phase.

Time to First Byte (TTFB)

The time between a browser sending an HTTP request and receiving the first byte of the response. Smaller HTML files reduce TTFB on uncached requests.

Inline Script

JavaScript placed directly in an HTML file inside <script> tags rather than loaded from an external file. Minifying inline scripts as part of HTML minification reduces their byte count without a separate build step.

Attribute Quoting

In HTML5, attribute values containing only alphanumeric characters, hyphens, underscores, periods, and colons may be written without quotes. Removing quotes from eligible attributes saves a small number of bytes per attribute.