liminfoHTML Minifier
Free web tool: HTML Minifier
About HTML Minifier
The HTML Minifier reduces the file size of HTML documents by stripping away whitespace and comments that are meaningful to developers but ignored by browsers. It applies four transformations to your code: HTML comments are removed entirely, consecutive whitespace between tags is collapsed to nothing, runs of multiple spaces or newlines within text content are reduced to a single space, and attribute spacing is normalized by removing spaces around the equals sign.
Frontend developers, performance engineers, and build pipeline authors use HTML minification to reduce page weight and improve load times. Even a modest reduction in HTML size can shave dozens of milliseconds from Time to First Byte on slow connections, and combined with Gzip compression the savings compound. This tool provides a fast, interactive way to preview exactly how much a specific HTML file shrinks before integrating a minifier into your build process.
The minification algorithm runs entirely in your browser as a pure JavaScript string transformation — no server round-trip, no file upload, no rate limits. After pasting or typing HTML into the input box and clicking Minify, the tool displays the compressed output, the original byte size, the minified byte size, and the percentage of bytes saved. You can copy the result with a single click and paste it into your production HTML file or build script.
Key Features
- Removes all HTML comments (<!-- ... -->) to eliminate developer-only annotations from production code
- Collapses all whitespace between HTML tags (>\s+<) to eliminate inter-element whitespace
- Reduces internal runs of multiple spaces and newlines to a single space using a global regex
- Normalizes attribute syntax by removing spaces around equals signs (class = "foo" → class="foo")
- Strips trailing spaces before closing > and self-closing /> tags
- Displays original file size in bytes and minified file size side by side for direct comparison
- Shows percentage of bytes saved in a highlighted green summary box
- One-click copy of minified output to clipboard — ready to paste into your production files
Frequently Asked Questions
What transformations does this HTML minifier apply?
The tool applies five transformations: (1) strips HTML comments, (2) collapses whitespace between tags, (3) reduces multiple spaces/newlines to a single space, (4) removes spaces around attribute equals signs, and (5) strips spaces before closing angle brackets. The result is a single-line HTML string with no unnecessary characters.
How much can HTML minification reduce file size?
Savings vary by how much whitespace and how many comments the original file contains. Well-indented HTML with many comments can shrink by 20–40%. Templates with little whitespace may see only 5–10% savings. The tool shows the exact byte count and percentage so you can evaluate the benefit for your specific file.
Will minification break my HTML page?
For standard HTML, minification is safe. Browsers treat whitespace between block elements as insignificant. However, content inside pre, textarea, or script tags where whitespace is semantically meaningful should be handled carefully. This tool collapses all whitespace globally, so if your page relies on preserved whitespace in inline content, test the output before deploying.
What is the difference between this tool and a build-time minifier?
This tool is designed for quick, interactive inspection — paste HTML, see the minified result instantly, check the savings. Build-time minifiers like html-minifier-terser are integrated into build pipelines (Webpack, Vite, Gulp) to process every file automatically. This tool is ideal for one-off checks, learning, and verifying what a minifier would produce.
Does minification affect SEO?
HTML minification does not affect SEO. Search engine crawlers parse the DOM, not the raw whitespace in your HTML source. Faster load times — one benefit of smaller HTML — can indirectly improve SEO rankings through Core Web Vitals signals like Largest Contentful Paint.
Should I minify HTML in addition to CSS and JavaScript?
Yes, minifying HTML is worthwhile, especially for server-rendered pages with large amounts of template markup. CSS and JavaScript minification typically provide larger savings because those files tend to contain more redundant whitespace and comments, but HTML minification adds additional benefit at no cost when it is part of your build pipeline.
Does this tool minify inline CSS and JavaScript?
No. This tool minifies the HTML structure only — it removes HTML comments and whitespace. Inline <style> blocks and <script> blocks are preserved as-is. To minify those, use dedicated CSS and JavaScript minifiers in addition to this HTML tool.
Can I use this output directly in production?
Yes. The output is valid, browser-parseable HTML. Paste it into your HTML file, template, or CMS. If your site is built with a framework like Next.js or Nuxt, those tools typically handle minification automatically during build — in that case, use this tool for inspection and verification rather than manual minification.