Modular HTML minifier, built on top of the PostHTML. Inspired by cssnano.

Documentation

https://htmlnano.netlify.app

Usage

npm install htmlnano

const htmlnano = require('htmlnano');
const options = {
    removeEmptyAttributes: false, // Disable the module "removeEmptyAttributes"
    collapseWhitespace: 'conservative' // Pass options to the module "collapseWhitespace"
};
// posthtml, posthtml-render, and posthtml-parse options
const postHtmlOptions = {
    sync: true, // https://github.com/posthtml/posthtml#usage
    lowerCaseTags: true, // https://github.com/posthtml/posthtml-parser#options
    quoteAllAttributes: false, // https://github.com/posthtml/posthtml-render#options
};

htmlnano
    // "preset" arg might be skipped (see "Presets" section below for more info)
    // "postHtmlOptions" arg might be skipped
    .process(html, options, preset, postHtmlOptions)
    .then(function (result) {
        // result.html is minified
    })
    .catch(function (err) {
        console.error(err);
    });

Also, you can use it as CLI tool:

node_modules/.bin/htmlnano --help

# STDIN -> STDOUT
cat test.html | node_modules/.bin/htmlnano > test.min.html

# Single file
node_modules/.bin/htmlnano test.html -o test.min.html

# Multiple files / globs (quote globs so htmlnano expands them itself)
node_modules/.bin/htmlnano "dist/**/*.html" --output-dir minified
node_modules/.bin/htmlnano "dist/**/*.html" --in-place

More usage examples (PostHTML, CLI, Webpack): https://htmlnano.netlify.app/usage

Benchmarks

Updated: 2026-11-13

| Website | Source (KB) | html-minifier-terser | html-minifier-next | htmlnano | minify | minify-html | swc-html | | --------------------------------------------------------------- | ----------: | ---------------------: | -------------------: | -------------------: | --------: | ------------: | ---------: | | alistapart.com | 65 | 13.9% | 25.2% | 38.1% | 10.1% | 11.3% | 10.7% | | developer.mozilla.org | 119 | 44.4% | 43.0% | 47.9% | 41.2% | 41.2% | 41.2% | | css-tricks.com | 183 | 41.5% | 19.6% | 25.6% | 11.1% | 11.3% | 12.7% | | mastodon.social | 45 | 22.7% | 14.4% | 14.0% | 5.7% | 6.9% | 7.9% | | en.wikipedia.org | 259 | 11.3% | 12.6% | 12.7% | 5.8% | 6.1% | 6.0% | | lafrenchtech.gouv.fr | 186 | 32.5% | 70.1% | 70.1% | 29.9% | 30.6% | 30.7% | | stackoverflow.blog | 135 | 28.8% | 7.9% | 7.6% | 4.6% | 5.0% | 5.5% | | edri.org | 85 | 24.6% | 34.7% | 33.8% | 11.3% | 10.6% | 11.7% | | eff.org | 54 | 18.1% | 19.5% | 18.3% | 13.4% | 12.3% | 13.0% | | w3.org | 48 | 28.7% | 28.7% | 28.3% | 23.7% | 23.6% | 23.6% | | html.spec.whatwg.org | 152 | 1.6% | 0.4% | 0.4% | 0.3% | 0.3% | 0.3% | | un.org | 161 | 23.6% | 45.4% | 44.9% | 19.2% | 16.9% | 16.7% | | apple.com | 250 | 19.7% | 11.8% | 10.8% | 7.6% | 6.7% | 6.5% | | home.cern | 292 | N/A | 23.8% | 26.3% | 8.1% | 9.8% | 10.2% | | weather.com | 455 | 14.2% | 9.7% | 9.0% | 7.2% | 7.0% | 7.1% | | github.com | 513 | 32.2% | 18.1% | 18.0% | 4.8% | 4.3% | 4.4% | | leanpub.com | 523 | 16.7% | 9.0% | 9.5% | 5.0% | 5.4% | 5.5% | | bbc.co.uk | 684 | 7.8% | 8.2% | 8.2% | 4.7% | 6.4% | 6.5% | | faz.net | 1353 | 7.7% | 13.3% | 18.1% | 4.3% | 4.6% | 9.2% | | tc39.es | 7637 | 9.1% | 7.9% | 7.3% | 6.5% | 6.0% | 6.1% | | Avg. minify rate | | 21.0% | 21.0% | 22.2% | 11.4% | 11.4% | 11.9% |

Latest benchmarks: https://github.com/maltsev/html-minifiers-benchmark (updated daily).