Registry / web-framework / express-minify-html

express-minify-html

JSON →
library0.12.0jsnpmunverified

express-minify-html is an Express middleware designed to automatically minify HTML responses generated by `res.render` calls. It leverages the robust `html-minifier` library under the hood, passing configuration options directly to it. The current stable version is 0.12.0. While there's no stated release cadence, its versioning suggests a pre-1.0 status, implying potential API changes in minor versions. A key differentiator is its seamless integration with Express's existing `res.render` function, with an option to `override` it directly or expose a new `res.renderMin` method. It also supports `exception_url` configurations, allowing developers to selectively bypass minification for specific routes using strings, regular expressions, or custom functions. This helps optimize performance by reducing HTML payload size for most requests without affecting critical or dynamic paths that might be sensitive to minification.

web-framework
npm install express-minify-html
github ↗package ↗
INSTALL
IMPORT
SIG · EXPRESS-MINIFY-HTM
E
express-minify-html
web-frameworkjavascriptv0.12.0
Install
—
Import
—
Disk
—
Pass rate
0/ 6
Env Coverage0 / 6
glibc
18–22
musl
18–22
Install & Compatibility
Where this runs
tested against v? · npm install
Install × environment matrix
Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux
musl
node 18–226 runs
build_error
glibc
node 18–226 runs
build_error
Code
Verified usage

Verified import paths — ran on the pinned version, not inferred.

minifyHTML
✓ const minifyHTML = require('express-minify-html');
✗ import minifyHTML from 'express-minify-html';
The package primarily uses CommonJS (`require`) syntax. Direct ESM `import` might not function as expected without specific transpilation or Node.js loader configurations.
app.use(minifyHTML(...))
✓ app.use(minifyHTML({ /* options */ }));
✗ app.use(minifyHTML);
The middleware factory function `minifyHTML` must be called with an options object (even if empty) to return the actual middleware function for `app.use`.

This quickstart demonstrates how to apply the `express-minify-html` middleware globally to an Express application, showing its effect on HTML rendered via `res.render`.

const express = require('express'); const minifyHTML = require('express-minify-html'); const path = require('path'); const app = express(); // Configure a simple view engine for demonstration app.set('views', path.join(__dirname, 'views')); app.set('view engine', 'ejs'); // Using EJS as an example // Create a dummy view file (e.g., views/helloTemplate.ejs) // console.log('Create views/helloTemplate.ejs with content like: <div> <h1>Hello <%= hello %></h1> <p> This is a paragraph. </p></div>'); app.use(minifyHTML({ override: true, exception_url: [], htmlMinifier: { removeComments: true, collapseWhitespace: true, collapseBooleanAttributes: true, removeAttributeQuotes: true, removeEmptyAttributes: true, minifyJS: true } })); app.get('/hello', function (req, res, next) { res.render('helloTemplate', { hello : 'world'}, function(err, html) { if (err) return next(err); console.log('Minified HTML output:\n' + html); // The output is minified res.send(html); }); }); app.get('/', (req, res) => { res.send('Go to /hello to see minified HTML'); }); const PORT = process.env.PORT ?? 3000; app.listen(PORT, () => { console.log(`Server listening on port ${PORT}`); console.log('Ensure you have a views/helloTemplate.ejs file.'); });
Debug
Known issues
gotchaSetting the `override` option to `false` will prevent the middleware from modifying the standard `res.render` function. Instead, you must explicitly call `res.renderMin` to get minified HTML. Failing to do so will result in unminified output.
fix
Either set `override: true` to have `res.render` automatically minify, or ensure all calls needing minification are updated to `res.renderMin` when `override` is `false`.
affects: >=0.1.0
gotchaIncorrect or overly aggressive configuration of the `htmlMinifier` options can lead to broken HTML, unexpected JavaScript behavior, or styling issues on the client-side. Always test minified output thoroughly.
fix
Carefully consult the official `html-minifier` documentation for recommended and safe configuration options. Start with basic options like `collapseWhitespace` and incrementally add others.
affects: >=0.1.0
gotchaThis package is designed for CommonJS (`require`). While modern Node.js environments might allow some interop, direct ESM `import` statements might not work correctly without specific bundler configurations (e.g., Webpack, Rollup) or Node.js loader setups.
fix
Use `const minifyHTML = require('express-minify-html');` for consistent behavior, especially in older Node.js projects or those not configured for ESM-CJS interop.
affects: <1.0.0
Errors
Common errors & fixes
Error: Cannot find module 'express-minify-html'
The `express-minify-html` package has not been installed or is not resolvable in the current project environment.
fix
Run `npm install express-minify-html` in your project directory.
TypeError: app.use is not a function
`app` is not an initialized Express application instance, or `express()` was not called.
fix
Ensure `const express = require('express');` and `const app = express();` are correctly set up before calling `app.use()`.
TypeError: minifyHTML is not a function
The `minifyHTML` symbol was imported incorrectly, often by attempting `import minifyHTML from 'express-minify-html'` in a CommonJS-first environment.
fix
Use `const minifyHTML = require('express-minify-html');` to correctly import the middleware factory.
Upgrade
Version history
0.12.0latest on npm
Audit
Dependencies
expressrequiredRequired for Express application integration as a middleware.
html-minifierrequiredCore dependency for the HTML minification logic.
Agent activity
2 hits · last 30 days
node
2
Resources
githubhttps://github.com/melonmanchan/express-minify-html ↗
packagehttps://www.npmjs.com/package/express-minify-html ↗
express-minify-html — npm install express-minify-html · libregistry