About HTML Minifier

Minify HTML with compression options. Part of the DevTools Surf developer suite. Browse more tools in the HTML collection.

Use Cases

• Reduce HTML payload size for email templates where download speed affects open rates on mobile.
• Minify server-rendered pages before caching in a CDN to reduce egress bandwidth costs.
• Strip development comments from production HTML before deployment.
• Compress static HTML files as part of a site generator build pipeline.

Tips

• Enable 'remove comments' and 'collapse whitespace' as a baseline — these two options alone typically reduce HTML size by 15-30%.
• Be cautious with 'remove optional tags' — omitting </li> or </td> closing tags is valid HTML5 but can confuse some parsers and older templating engines.
• Minify HTML as the last build step, after all templating and component rendering is complete, to avoid mangling template syntax.

Fun Facts

• HTML whitespace collapse was specified in the CSS 2.1 spec (2006) — adjacent whitespace characters in HTML are rendered as a single space, making all internal whitespace between tags safe to remove.
• Google's PageSpeed study (2018) found that reducing HTML payload by 100KB improved Time to First Byte by 8ms on median mobile connections — meaningful at scale for high-traffic pages.
• The HTML5 specification formally documents which end tags are optional: </html>, </head>, </body>, </li>, </dt>, </dd>, </p>, </td>, </th>, and </tr> can all be legally omitted.

FAQ

Is minified HTML still valid?

Yes — all minification options produce spec-valid HTML5. Optional-tag removal is the most aggressive option; conservative mode preserves all tags while still collapsing whitespace and removing comments.

Does it minify inline CSS and JS?

Yes — inline <style> blocks are passed through a CSS minifier and inline <script> blocks through a JS minifier. External files referenced by src/href are not touched.

How much size reduction can I expect?

Typical results: 15-30% for content-heavy pages, 5-15% for heavily-templated apps where most markup is already compact. Minification compounds with gzip, which reduces already-minified text further.