CSS & JS Minifier – Minify Code Online Free
Minify CSS and JavaScript files online for free. Reduce file size instantly with size savings percentage shown—copy or download your minified output. Browser-based, no uploads.
Runs in your browser
WebAssembly, no server
No signup required
Open and use instantly
Files stay private
Nothing leaves your device
How It Works
Select CSS or JavaScript as the code type
Paste your CSS or JS code into the input area
Click 'Minify' to process the code
Key Features
- Minify CSS — removes whitespace, comments, shortens values
- Minify JavaScript — removes whitespace and comments
- Shows original and minified file sizes
- Percentage size reduction shown
- Copy minified code to clipboard
- Paste code directly or type in the editor
- No sign-up required
- 100% browser-based — code never uploaded
- Free with no limits
- Handles large files efficiently
- Mobile-friendly interface
About This Tool
Our CSS & JS Minifier reduces the file size of your CSS and JavaScript code by removing unnecessary characters — whitespace, comments, and applying safe optimizations — making your website faster.
Why Minify CSS and JavaScript?
- Faster page load: smaller files download quicker
- Better Core Web Vitals: LCP and FID improve with smaller JS bundles
- Reduced bandwidth: less data transferred per page view
- Better SEO: Google uses page speed as a ranking factor
CSS Minification Removes
- Whitespace and line breaks
- Comments (/ ... /)
- Redundant semicolons
- Shortens hex colors (#FFFFFF → #FFF)
- Removes zero units (0px → 0)
JavaScript Minification Does
- Removes whitespace and comments
- Shortens local variable names
- Removes dead code
Size Savings
Typical CSS minification reduces file size by 20–40%. JS minification with variable renaming can reduce size by 30–60%.
When to Minify
Always minify production CSS and JS. Keep source (unminified) copies for development. Build tools like webpack and Vite do this automatically in production builds.
Frequently Asked Questions
Yes — minification only removes whitespace, comments, and performs safe syntax-level optimizations. The code behaves identically.
Yes. Minification does not change the logic or functionality of code — it only removes characters that computers don't need to execute it.
CSS typically reduces 20–40%. JavaScript typically reduces 30–60% with variable renaming. Savings vary by codebase.
This tool focuses on CSS and JavaScript. For HTML minification, use a dedicated HTML minifier.
Yes — always keep source files. Minified code is hard to read and debug. Use minified versions only for production deployment.
No. All minification runs in your browser. Your code never leaves your device.
Yes — completely free with no sign-up.
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