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HTMLMinifier is a highlyconfigurable,well-tested, JavaScript-based HTML minifier.

From NPM for use as a command line app:

npm install html-minifier-terser -g

From NPM for programmatic use:

npm install html-minifier-terser

Note that almost all options are disabled by default. Experiment and find what works best for you and your project.

For command line usage please seehtml-minifier-terser --help for a list of available options.

Sample command line:

html-minifier-terser --collapse-whitespace --remove-comments --minify-jstrue

const{ minify}=require('html-minifier-terser');constresult=awaitminify('<p title="blah">foo</p>',{removeAttributeQuotes:true,});result;// '<p title=blah id=moo>foo</p>'

Seecorresponding blog post for all the gory details ofhow it works,description of each option,testing results andconclusions.

Also see correspondingRuby wrapper, and for Node.js,Grunt plugin,Gulp plugin,Koa middleware wrapper andExpress middleware wrapper.

For lint-like capabilities take a look atHTMLLint.

How does HTMLMinifier compare to other solutions —HTML Minifier from Will Peavy (1st result inGoogle search for "html minifier") as well ashtmlcompressor.com andminimize?

Most of the options are disabled by default.

Minifier options likesortAttributes andsortClassName won't impact the plain-text size of the output. However, they form long repetitive chains of characters that should improve compression ratio of gzip used in HTTP compression.

If you have chunks of markup you would like preserved, you can wrap them<!-- htmlmin:ignore -->.

You can minify script tags with JSON-LD by setting the option{ processScripts: ['application/ld+json'] }. Note that this minification is very rudimentary, it is mainly useful for removing newlines and excessive whitespace.

SVG tags are automatically recognized, and when they are minified, both case-sensitivity and closing-slashes are preserved, regardless of the minification settings used for the rest of the file.

HTMLMinifiercan't work with invalid or partial chunks of markup. This is because it parses markup into a tree structure, then modifies it (removing anything that was specified for removal, ignoring anything that was specified to be ignored, etc.), then it creates a markup out of that tree and returns it.

Input markup (e.g.<p>foo)

↓

Internal representation of markup in a form of tree (e.g.{ tag: "p", attr: "id", children: ["foo"] })

↓

Transformation of internal representation (e.g. removal ofid attribute)

↓

Output of resulting markup (e.g.<p>foo</p>)

HTMLMinifier can't know that original markup was only half of the tree; it does its best to try to parse it as a full tree and it loses information about tree being malformed or partial in the beginning. As a result, it can't create a partial/malformed tree at the time of the output.

Benchmarks for minified HTML:

cd benchmarksnpm installnpm run benchmark

npm run serve