---
id: rcssmin
version: "1.2.2"
license: Apache License, Version 2.0
license_treatment: permissive
maintenance: aging
---

# rcssmin — CSS Minifier

License: permissive · Maintenance: aging · Downloads: 2.9M/mo

## What it is and what it does

RCSSmin is a CSS minifier that reduces CSS file size by removing whitespace, comments, and optional semicolons while preserving the stylesheet's functionality. It performs syntactical compression only—it strips unnecessary characters but does not restructure or optimize CSS rules semantically. The package is implemented in C for speed, making it suitable for runtime use rather than just build-time preprocessing, though it also supports Python 2.7 and Python 3.6 and later.

The minifier recognizes CSS syntax quirks including the nesting selector (&), unicode escapes, data URLs, and several browser-specific hacks (IE7, Mac-IE5, and IE6 workarounds). It keeps CSS strings intact and can optionally preserve comments marked with an exclamation mark. With no runtime dependencies, it installs as a compiled extension across many Linux platforms and Python versions.

Use it for:

- Minify CSS at runtime in web applications to reduce bandwidth and improve page load times without a separate build step.
- Process user-uploaded or dynamically generated CSS stylesheets before serving them to clients.
- Integrate CSS compression into a Python-based static site generator or template system.
- Reduce CSS file size in embedded or IoT applications where storage and transmission are constrained.
- Preprocess CSS in a web framework middleware to automatically compress stylesheets on the fly.

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

RCSSmin minifies CSS by removing spaces, comments, and unnecessary characters while preserving CSS semantics and supporting common CSS hacks.

Yes, if you need runtime CSS minification in Python and are comfortable with a C-compiled dependency. The package is stable (Production/Stable status), has no known vulnerabilities, and is well-established (in top 5000 PyPI packages by downloads). However, the 306-day gap since the last release and aging maintenance status suggest limited active development; verify that the package still meets your platform and Python version requirements before relying on it for new projects.

## Install

pip install rcssmin
uv add rcssmin
poetry add rcssmin

## Installing rcssmin

Before you install: Medium install friction due to compiled C extensions across multiple platform wheels (manylinux, musllinux, aarch64). No runtime dependencies. Last release was 306 days ago; maintenance status is aging.

License in practice: Licensed under Apache License Version 2.0, a permissive open-source license. You may use, modify, and distribute the package freely in commercial and private projects with minimal restrictions.

Quickstart:

pip install rcssmin

import rcssmin
minified = rcssmin.cssmin('body { color: red; /* comment */ }')

Verify before relying:

- Whether the C extension is reliably built and tested on all advertised platforms (manylinux, musllinux, aarch64)
- Current maintenance status and whether the 306-day gap since last release indicates active or dormant development
- Performance improvement claims ('factor 100 or so') and whether they hold on modern Python versions

## Package facts

- License: Apache License, Version 2.0 (permissive)
- Python support: unspecified
- Install friction: medium
- Maintenance: aging
- Downloads: 2.9M/month (top 5,000 on PyPI)
- Known vulnerabilities: none known

## Tags

css minifier, css compression, remove css whitespace, css optimizer, lightweight css minification, runtime css minifier, css syntax compressor, css-optimization, web-performance

[View on SkillFed](https://skillfed.io/packages/rcssmin) · [View on PyPI](https://pypi.org/project/rcssmin/)