Online HTML, CSS & JavaScript Minifier

Reduce the file size of your code by removing unnecessary characters without altering functionality. Paste your code below to minify it instantly.

Input HTML:
Minified HTML:
Input CSS:
Minified CSS:
Input JavaScript:
Minified JavaScript:

About Code Minification

Minification (also minimisation or minimization), is the process of removing all unnecessary characters from source code without changing its functionality. These unnecessary characters usually include white space characters, new line characters, comments, and sometimes block delimiters, which are used to add readability to the code but are not required for it to execute.

Benefits of Minification:

  • Reduced File Size: Leads to faster download times for your users.
  • Improved Performance: Quicker parsing and execution by browsers or JavaScript engines.
  • Lower Bandwidth Consumption: Saves data for users, especially on mobile networks, and reduces hosting costs.
  • Obfuscation (Minor): While not its primary goal, minified code is harder to read, offering a slight deterrent to casual inspection.

How This Tool Works:

  • HTML Minification: Removes comments, collapses whitespace, and can optionally remove attributes quotes, etc. We use a client-side JavaScript library for this.
  • CSS Minification: Removes comments, whitespace, and can optimize some CSS properties. The current implementation is basic; for complex scenarios, build tools offer more advanced features like selector merging.
  • JavaScript Minification: We use Terser, a powerful JavaScript parser, mangler and compressor toolkit. It can significantly reduce JS file sizes by shortening variable names, removing dead code, and more.
  • Client-Side Processing: All minification happens directly in your browser. Your code is not sent to any server.

Note: Always test your minified code thoroughly to ensure it behaves as expected, as aggressive minification can sometimes introduce subtle issues, especially with JavaScript.

About Code Minifier

What does this tool do?

Our Online Code Minifier optimizes HTML, CSS, and JavaScript files by removing unnecessary characters, whitespace, and comments while preserving functionality. It uses advanced algorithms including Terser for JavaScript optimization, providing real-time compression statistics and client-side processing for maximum security.

Why is this useful?

Code minification significantly reduces file sizes, improving website loading speed, reducing bandwidth usage, and enhancing user experience. Smaller files mean faster downloads, especially on mobile networks, and better search engine rankings due to improved page speed metrics.

Who uses this tool?

  • Web developers - Optimize website assets for production deployment
  • Frontend engineers - Reduce bundle sizes and improve application performance
  • DevOps teams - Integrate into build pipelines for automated optimization
  • Website owners - Improve site speed without changing functionality
  • SEO specialists - Enhance page speed scores for better search rankings

How to minify your code

  1. Select the appropriate tab: HTML, CSS, or JavaScript
  2. Paste your source code into the input textarea
  3. Click the "Minify" button for your chosen code type
  4. Review compression statistics showing size reduction percentage
  5. Copy the optimized code using the "Copy Minified" button
  6. Test the minified code to ensure it works as expected

Example

A 15KB JavaScript file with comments and formatting reduces to 8KB (47% smaller) after minification, while a 5KB CSS file becomes 3.2KB (36% reduction). These savings multiply across all website assets for significant performance gains.

Understanding minification results

Size Reduction
Percentage and absolute byte reduction achieved through minification. Higher percentages indicate more effective optimization.
HTML Minification
Removes comments, collapses whitespace, and eliminates unnecessary spaces between tags while preserving functionality.
CSS Minification
Strips comments, removes whitespace, eliminates unnecessary semicolons, and optimizes property formatting.
JavaScript Minification
Uses Terser engine for advanced optimization including variable name shortening, dead code elimination, and compression.
Client-Side Processing
All minification occurs in your browser - no code is transmitted to external servers, ensuring privacy and security.

Effective minification indicators

  • 20-50% size reduction: Typical savings for well-formatted source code
  • Preserved functionality: Code operates identically after minification
  • Faster loading: Reduced download times especially on slower connections
  • Lower bandwidth usage: Decreased server costs and mobile data consumption

Minification considerations

  • Testing required: Always verify minified code works correctly
  • Debugging difficulty: Minified code is harder to read and debug
  • Source maps needed: Use source maps for debugging minified JavaScript
  • Limited CSS optimization: Advanced CSS optimizations require specialized tools

Best practices for minification

  • Keep original source files for development and maintenance
  • Use minified files only in production environments
  • Implement automated minification in build processes
  • Generate source maps for debugging minified JavaScript
  • Test thoroughly across different browsers and devices

Common use cases

Website Performance Optimization

Reduce file sizes for faster page loading, improved user experience, and better search engine rankings through reduced bounce rates.

Build Pipeline Integration

Automate code optimization in deployment workflows, ensuring production code is always optimized without manual intervention.

Mobile Optimization

Minimize data usage for mobile users by reducing asset sizes, especially important for users on limited data plans.

CDN and Caching

Optimize files before uploading to content delivery networks, maximizing cache efficiency and reducing bandwidth costs.

Advanced minification features

JavaScript minification uses Terser for advanced optimizations including variable name mangling, function hoisting, and dead code elimination. HTML and CSS minification focus on safe whitespace and comment removal.

Privacy and security

All code processing happens locally in your browser using client-side JavaScript. No source code is transmitted to external servers, ensuring complete privacy and security of your intellectual property.

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