This is a paragraph with extra spaces.
\n \n\n\n`;\n\nconst minifiedHtml = minify(html, {\n removeComments: true,\n collapseWhitespace: true,\n collapseBooleanAttributes: true,\n removeEmptyAttributes: true,\n removeOptionalTags: true,\n minifyJS: true,\n minifyCSS: true,\n useShortDoctype: true,\n sortAttributes: true,\n sortClassName: true,\n decodeEntities: true,\n});\n\nconsole.log(minifiedHtml);\n/* Expected output:\nThis is a paragraph with extra spaces.
\n*/","lang":"javascript","description":"This quickstart demonstrates how to programmatically minify an HTML string using a comprehensive set of common options for maximum compression, showing before and after output."},"warnings":[{"fix":"Upgrade your Node.js environment to version 6 or higher, or pin `html-minifier` to a version lower than 4.0.0 if unable to upgrade Node.js.","message":"Version 4.0.0 of `html-minifier` dropped support for Node.js versions older than 6. Projects running on Node.js 0.x or 4.x will encounter errors.","severity":"breaking","affected_versions":">=4.0.0"},{"fix":"Thoroughly review the extensive list of available options in the documentation and enable them based on your project's needs. A good starting point is often `collapseWhitespace`, `removeComments`, `minifyJS`, and `minifyCSS`.","message":"By default, almost all minification options are disabled. Users must explicitly enable desired minification features (e.g., `collapseWhitespace`, `removeComments`) to achieve any compression. Unexpectedly large output is often due to not configuring options.","severity":"gotcha","affected_versions":">=1.0.0"},{"fix":"Ensure the input HTML is well-formed and complete before passing it to `html-minifier`. For templating engines that output fragments, consider minifying the full, rendered HTML page.","message":"`html-minifier` cannot reliably process invalid or partial HTML markup. It parses the input into a tree structure, and malformed input can lead to unexpected or incorrect output, as it attempts to interpret it as a complete, valid tree.","severity":"gotcha","affected_versions":">=1.0.0"},{"fix":"For projects requiring ES6+ JavaScript minification, configure a custom `minifyJS` function with a modern minifier like Terser, or consider using `html-minifier-terser` which bundles Terser directly. Version 4.x updates its dependencies, but this note is particularly relevant for older versions.","message":"The default JavaScript minification library, UglifyJS, used by `html-minifier` for `minifyJS`, is not actively maintained and does not support modern JavaScript syntax (ES6+). This can lead to issues with contemporary JavaScript code.","severity":"deprecated","affected_versions":"<4.0.0"},{"fix":"Consider migrating to `html-minifier-next` for ongoing development, as it addresses many limitations and provides a more up-to-date solution for HTML minification.","message":"There is a newer, actively maintained alternative called `html-minifier-next` (and `html-minifier-terser`) that offers improved features, dependency updates, and better support for modern web standards and Node.js versions.","severity":"gotcha","affected_versions":">=1.0.0"}],"env_vars":null,"last_verified":"2026-04-19T00:00:00.000Z","next_check":"2026-07-18T00:00:00.000Z","problems":[{"fix":"The module exports an object. You need to destructure or access the `minify` function: `const { minify } = require('html-minifier');` or `const minify = require('html-minifier').minify;`.","cause":"Attempting to call the `html-minifier` module export directly as a function, rather than accessing its `minify` method.","error":"TypeError: htmlMinifier is not a function"},{"fix":"Upgrade your Node.js installation to version 6 or newer. Alternatively, if upgrading Node.js is not possible, downgrade `html-minifier` to a version compatible with your current Node.js setup (e.g., `npm install html-minifier@3` for Node.js < 6).","cause":"Running `html-minifier` version 4.0.0 or higher on an unsupported Node.js environment.","error":"Error: The 'html-minifier' package requires Node.js version 6 or higher. You are running Node.js version 4.x.x."},{"fix":"Provide an options object to the `minify` function with desired features enabled, such as `collapseWhitespace: true`, `removeComments: true`, `minifyJS: true`, `minifyCSS: true`, etc.","cause":"Most minification options are disabled by default and must be explicitly enabled.","error":"Minified HTML output is not significantly smaller or comments/whitespace are still present."},{"fix":"For JavaScript, consider using a custom `minifyJS` function with a modern minifier like Terser that supports ES6+. For CSS, ensure the inline CSS is valid. If the issue persists, disable inline minification for the problematic section or entire document.","cause":"The default inline JavaScript (UglifyJS) or CSS (Clean-CSS) minifiers do not support modern syntax (e.g., ES6+ JavaScript) or encounter malformed input.","error":"SyntaxError: Invalid or unexpected token in inline JavaScript/CSS during minification."}],"ecosystem":"npm"}