CSS Minifier

Minify CSS online with CSSO: merge rules, remove overrides, and restructure stylesheets for smaller files, in your browser

CSS Input

Minified CSS

CSS Minifier Tips

Powered by CSSO - a structural optimizer that merges and restructures rules, not just a whitespace stripper.
Overridden declarations are removed automatically: later rules win, earlier duplicates disappear.
margin: 0px becomes margin: 0 and colors like #ff0000 become red where shorter.
Load the sample to see rule merging in action - overridden properties simply vanish.

Professional CSS Minifier Processing Features

Everything you need to work with CSS Minifier data efficiently and professionally

CSSO Engine

A structural CSS optimizer that understands the cascade, not just a whitespace stripper.

Clean Output

Comments stripped, whitespace collapsed, declarations folded to shortest form.

Rule Merging

Duplicate and overridden declarations disappear while the cascade stays intact.

Safe Optimization

Declarations are only removed when a later rule guarantees to override them.

Size Report

Bytes before and after, plus the exact percentage saved, on every run.

Private by Design

Your styles stay in the browser tab. Nothing is uploaded, ever.

How It Works

Simple steps to process your CSS Minifier like a pro

Paste Your CSS

Copy a stylesheet, a component style block, or compiled CSS into the input area.

Click Minify

CSSO restructures the rules in your browser - merging, folding and stripping.

Check the Report

See the byte count before and after, plus the percentage saved.

Copy the Output

Copy the minified CSS into your build, CDN, or production page.

Professional CSS Minifier Formatter & Validator

CSS Minifier processing runs entirely in your browser — no uploads, no accounts, no limits.

Built by Experts

The CSS Minifier formatting engine runs locally in your browser using established parsers and standard algorithms. Nothing is hidden — open your browser dev tools and watch it work.

Key Technical Features:

• Real CSSO engine running fully in your browser
• Structural optimization merges rules and removes overridden declarations
• Shorthand folding and shorter equivalent values (colors, units, zeros)
• Byte-accurate size report with before/after comparison and savings percentage
• Engine loads lazily from CDN - the page stays fast until you click Minify

Trusted & Secure

Your data stays in your browser: nothing is uploaded, stored, or logged. Close the tab and it is gone.

Security & Privacy:

• 100% client-side minification - your styles never leave the browser
• No tracking, cookies or data logging
• HTTPS encryption for secure connections
• Design tokens and client CSS stay on your device
• GDPR and CCPA compliant approach

Why Professionals Choose EZ Formatter

100%

Client-side processing

Data sent to servers

Tools in the workbench

Your data stays in your browser

Frequently Asked Questions

Common questions about Css Minifier formatting answered

Yes, completely free with no registration. All minification happens locally in your browser.

CSSO (CSS Optimizer) - a structural optimizer from the Yandex/Ozon ecosystem that merges selectors, folds shorthands and removes overridden declarations, going well beyond simple whitespace removal.

No. CSSO preserves the cascade: declarations removed are ones guaranteed to be overridden later, so the rendered result is identical.

No - those need to be compiled to CSS first. Feed the compiled .css output here for the final size squeeze.

Readable, well-indented CSS typically shrinks 40-70% thanks to whitespace removal plus CSSO restructuring. The size report shows the exact savings.