CSS HTML JS Minifier

2.5.5 · maintenance · verified Thu Apr 16

CSS-HTML-JS-Minify is a standalone, asynchronous, cross-platform, and Unicode-ready Python 2 and 3 library for minifying web assets (CSS, HTML, JavaScript). It can process single files or entire folders, offering features like GZIP compression, SHA1 hashing for filenames, and optional alphabetical sorting of CSS properties. The current version is 2.5.5, last updated in 2018, indicating a maintenance-oriented release cadence.

Common errors

```
AttributeError: 'module' object has no attribute 'hash'
```
cause Attempting to use `hash=True` as an argument in the Python API for minification functions.

fix The correct argument name for adding a SHA1 hash to filenames in the Python API is `add_hash`. Change `hash=True` to `add_hash=True`.
```
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position ...
```
cause Using standard input/output streams with files containing non-ASCII (Unicode) characters, which is a deprecated usage pattern for this library.

fix Avoid piping input/output using `sys.stdin`/`sys.stdout`. Instead, read file content directly into a string and pass it to `html_minify`, `css_minify`, or `js_minify`, or use the `process_single_..._file` functions with file paths.
```
TypeError: process_single_html_file() got an unexpected keyword argument 'hash'
```
cause Passing the `hash` argument to file processing functions like `process_single_html_file` directly, or other minification functions, when `add_hash` is the expected parameter name.

fix Ensure you are using `add_hash=True` (or `add_hash=False`) for the hash functionality in the Python API, not `hash`.

Warnings

deprecated The use of Std-In to Std-Out for minification is deprecated due to potential issues with Unicode characters. It is recommended to process files directly or pass strings to the API functions.
Fix: Avoid piping input/output via standard streams. Use `process_single_..._file` functions or `..._minify` for strings.
gotcha The CLI flags `--comments` and `--overwrite` are explicitly marked as 'Not Recommended' in the documentation. Keeping comments can reduce minification effectiveness, and overwriting files without backup can lead to data loss.
Fix: Exercise caution when using `--comments` and `--overwrite`. Consider using version control or `output_path` for backups.
gotcha There is an inconsistency between the CLI argument `--hash` for adding a SHA1 hash to filenames and its Python API equivalent, which is `add_hash`. Using `hash` in the Python API will result in an error.
Fix: When using the Python API, pass `add_hash=True` instead of `hash=True` to enable SHA1 hashing for filenames.
gotcha The `--watch` feature, which re-compresses files upon changes, operates with a minimum delay of approximately 60 seconds between runs. This means file changes might not be reflected immediately.
Fix: Be aware of the ~60-second polling interval for the `--watch` functionality; real-time updates are not supported.

Install

pip install css-html-js-minify Install stable version

Imports

process_single_html_file

from css_html_js_minify import process_single_html_file

process_single_js_file

from css_html_js_minify import process_single_js_file

process_single_css_file

from css_html_js_minify import process_single_css_file

html_minify

from css_html_js_minify import html_minify

js_minify

from css_html_js_minify import js_minify

css_minify

from css_html_js_minify import css_minify

Quickstart

This quickstart demonstrates both string-based minification and file processing for HTML, CSS, and JavaScript. For file processing, it shows how to either overwrite the original file or create a new minified file with a specified output path.

from css_html_js_minify import (html_minify, js_minify, css_minify,
                                  process_single_html_file, process_single_js_file)

# Minify strings
minified_html = html_minify(' <p>yolo<a href="/" >o </a > <!-- hello --></p>')
print(f"Minified HTML string: {minified_html}")

minified_js = js_minify('var i = 1; i += 2 ;\n alert( "hello " ); //hi')
print(f"Minified JS string: {minified_js}")

minified_css = css_minify('body {width: 50px;}\np {margin-top: 1em;/* hi */ }', comments=False)
print(f"Minified CSS string: {minified_css}")

# Example for file processing (creates dummy files first)
with open('test.htm', 'w') as f:
    f.write('<html><body><!-- comment --><h1>Hello</h1></body></html>')
with open('test.js', 'w') as f:
    f.write('function greet() { console.log("Hello"); // Comment }')

process_single_html_file('test.htm', overwrite=True) # Overwrites test.htm with minified content
process_single_js_file('test.js', overwrite=False, output_path='test.min.js') # Creates test.min.js

print("Minification of test.htm and test.js completed. Check generated files.")

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