HTMLMinifier is a highly configurable, well-tested, Javascript-based HTML minifier, with lint-like capabilities.
See corresponding blog post for all the gory details of how it works, description of each option, testing results and conclusions.
Test suite is available online.
Also see corresponding Ruby wrapper, and for Node.js, Grunt plugin & Gulp module.
How does HTMLMinifier compare to another solution — HTML Minifier from Will Peavy (1st result in google search for "html minifier")?
| Site | Original size (KB) | HTMLMinifier (KB) | Will Peavy (KB) |
|---|---|---|---|
| Wikipedia | 401.4 | 385.5 | 396.3 |
| Stackoverflow | 200.4 | 165.3 | 168.3 |
| MSN | 160 | 141 | 145 |
| Amazon | 245.9 | 237.1 | 225 |
| ES6 table | 117.9 | 82 | 92 |
| HTMLMinifier page | 48.8 | 41.3 | 43.3 |
| Eloquent Javascript | 890 | 860 | 872 |
Installing with npm:
npm install html-minifier
| Option | Description | Default |
|---|---|---|
removeComments |
Strip HTML comments | false |
removeCommentsFromCDATA |
Strip HTML comments from scripts and styles | false |
removeCDATASectionsFromCDATA |
Remove CDATA sections from script and style elements | false |
collapseWhitespace |
Collapse white space that contributes to text nodes in a document tree. | false |
conservativeCollapse |
Always collapse to 1 space (never remove it entirely) | false |
collapseBooleanAttributes |
Omit attribute values from boolean attributes | false |
removeAttributeQuotes |
Remove quotes around attributes when possible. | false |
removeRedundantAttributes |
Remove attributes when value matches default. | false |
useShortDoctype |
Replaces the doctype with the short (HTML5) doctype | false |
removeEmptyAttributes |
Remove all attributes with whitespace-only values | false |
removeOptionalTags |
Remove unrequired tags | false |
removeEmptyElements |
Remove all elements with empty contents | false |
lint |
Toggle linting | false |
keepClosingSlash |
Keep the trailing slash on singleton elements | false |
caseSensitive |
Treat attributes in case sensitive manner (useful for SVG; e.g. viewBox) | false |
minifyJS |
Minify Javascript in script elements and on* attributes (uses UglifyJS) | false (could be true, false, Object (options)) |
minifyCSS |
Minify CSS in style elements and style attributes (uses clean-css) | false (could be true, false, Object (options)) |
ignoreCustomComments |
Array of regex'es that allow to ignore certain comments, when matched | [ ] |
processScripts |
Array of strings corresponding to types of script elements to process through minifier (e.g. "text/ng-template", "text/x-handlebars-template", etc.) | [ ] |
Chunks of markup can be ignored by wrapping them with <!-- htmlmin:ignore -->.
