simple-minify-html

[!CAUTION] This is a small fork of wilsonlin's great minify-html, you should probably use that instead.

Changes include, but are not limited to:

• No support for other platforms than Rust
• Uses OXC for JavaScript minification over minify-js
• Does not support templating syntax
• Less configuration options
• No options that might leave the output not spec compliant

View the changelog to see the latest updates.

Get

[dependencies]
simple-minify-html = "0.16.0"

Use

Check out the docs for API and usage examples.

Features

JavaScript minification

To enable minification of JavaScript, enable the js feature and this will automatically be handled:

[dependencies]
simple-minify-html = { version = "0.16.0", features = ["js"] }

CSS minification

To enable minification of JavaScript, enable the js feature and this will automatically be handled:

[dependencies]
simple-minify-html = { version = "0.16.0", features = ["css"] }

Minification

Spec compliance

WHATWG is the current HTML standard and obsoletes all previous standards. WHATWG lists suggested validators here.

To minify even further, it's possible to enable options that may output HTML that doesn't fully pass validation, but is still interpreted and rendered correctly according to the WHATWG parsing specification, which major browser engines ( Firefox, Chrome, Safari) implement. Refer to these options:

• allow_noncompliant_unquoted_attribute_values
• allow_optimal_entities
• allow_removing_spaces_between_attributes
• minify_doctype

In Rust, Cfg::enable_possibly_noncompliant can enable all of these at once.

Whitespace

minify-html has advanced context-aware whitespace minification that does things such as:

• Leave whitespace untouched in pre and code, which are whitespace sensitive.
• Trim and collapse whitespace in content tags, as whitespace is collapsed anyway when rendered.
• Remove whitespace in layout tags, which allows the use of inline layouts while keeping formatted code.

Methods

There are three whitespace minification methods. When processing text content, minify-html chooses which ones to use depending on the containing element.

<p>↵
    ··The·quick·brown·fox↵
    ··jumps·over·the·lazy↵
    ··dog.↵
</p>

<p>·The·quick·brown·fox·jumps·over·the·lazy·dog.·</p>

<ul>↵
    ··
    <li>A</li>
    ↵
    ··
    <li>B</li>
    ↵
    ··
    <li>C</li>
    ↵
</ul>

<ul>↵
    ··
    <li>A</li>
    <li>B</li>
    <li>C</li>
    ↵
</ul>

<p>↵
    ··Hey,·I·<em>just</em>·found↵
    ··out·about·this·<strong>cool</strong>·website!↵
    ··<sup>[1]</sup>↵
</p>

<p>Hey,·I·<em>just</em>·found↵
    ··out·about·this·<strong>cool</strong>·website!↵
    ··<sup>[1]</sup></p>

Element types

minify-html assumes HTML and SVG elements are used in specific ways, based on standards and best practices. By making these assumptions, it can apply optimal whitespace minification strategies. If these assumptions do not hold, consider adjusting the HTML source or turning off whitespace minification.

<p>↵
    ··Hey,·I·<em>just</em>·found↵
    ··out·about·this·<strong>cool</strong>·website!↵
    ··<sup>[1]</sup>↵
</p>

<p>Hey,·I·<em>just</em>·found·out·about·this·<strong>cool</strong>·website!·<sup>[1]</sup></p>

<ul>↵
    ··
    <li>A</li>
    ↵
    ··
    <li>B</li>
    ↵
    ··
    <li>C</li>
    ↵
</ul>

<ul>
    <li>A</li>
    <li>B</li>
    <li>C</li>
</ul>

<li>↵
    ··
    <article>↵
        ····
        <section></section>
        ↵
        ····
        <section></section>
        ↵
        ··
    </article>
    ↵
</li>

<li>
    <article>
        <section></section>
        <section></section>
    </article>
</li>

Tags

Optional opening and closing tags are removed.

Attributes

Any entities in attribute values are decoded, and then the shortest representation of the value is calculated and used:

• Double quoted, with any " encoded.
• Single quoted, with any ' encoded.
• Unquoted, with "/' first character (if applicable), any >, and any whitespace encoded.

Attributes have their whitespace (after any decoding) trimmed and collapsed when possible.

Boolean attribute values are removed. Some other attributes are completely removed if their value is empty or the default value after any processing.

type attributes on script tags with a value equaling a JavaScript MIME type are removed.

If an attribute value is empty after any processing, everything but the name is completely removed (i.e. no =), as an empty attribute is implicitly the same as an attribute with an empty string value.

Spaces are removed between attributes when possible.

Entities

Entities are decoded if they're valid and shorter or equal in length when decoded. UTF-8 sequences that have a shorter entity representation are encoded.

Numeric entities that do not refer to a valid Unicode Scalar Value are replaced with the replacement character.

Encoding is avoided when possible; for example, < are only encoded in content if they are followed by a valid tag name character. If necessary, the shortest entity representation is chosen.

Comments

Comments are removed.

Ignored

Bangs, processing instructions, and empty elements are not removed as it is assumed there is a special reason for their declaration.

Parsing

minify-html can process any HTML, handling all possible syntax (including invalid ones) gracefully like browsers. See Parsing.md for more details.

Issues and contributions

Pull requests and any contributions welcome!

If minify-html did something unexpected, misunderstood some syntax, or incorrectly kept/removed some code, raise an issue with some relevant code that can be used to reproduce and investigate the issue.