JavaScript Minifier & Beautifier
Compress or beautify JavaScript code with customizable options
JavaScript Minifier & Beautifier Documentation
What is this tool?
This tool allows you to compress (minify) or beautify JavaScript code. Minification removes unnecessary whitespace, comments, and redundant characters to reduce file size for production deployment. Beautification formats JavaScript with proper indentation and line breaks for better readability during development.
Key Features
- Minify JS to reduce file size (removes comments/whitespace)
- Beautify JS (Pretty Print) with adjustable indentation
- Safe processing (no variable mangling)
- Supports modern ES6+ syntax
- 100% client-side execution
Common Use Cases
- Compressing production assets for faster load times
- Formatting legacy or minified code for debugging
- Cleaning up inconsistent indentation
- Quickly unminifying library code to understand logic
How to Use JavaScript Minifier
Our tool supports two primary modes: Minification for production deployment and Beautification for development and debugging. Switch between modes using the toggle buttons at the top.
To Compress JavaScript:
- Paste your source code into the Input JavaScript area, or click 'Load Sample'.
- Select 'Minify' mode (default). Optionally check 'Preserve Comments' if you need to keep license headers.
- Click 'Process'. The compressed code will appear in the output area along with cornmpression stats.
To Format/Beautify JavaScript:
- Paste minified or messy code into the input area.
- Select 'Beautify' mode. You can customize the Indent Size (2, 4 spaces or Tab) to match your coding style.
- Click 'Process' to get perfectly indented, readable code.
Why optimize JavaScript? Performance & Best Practices
Minifying JavaScript is a crucial step in modern web development performance optimization. By removing whitespace, comments, and unnecessary characters, you significantly reduce the file size of your scripts. Smaller files mean faster download times for your users, especially on mobile networks. This directly improves your website's Core Web Vitals (specifically LCP and FID), which are key ranking factors for search engines like Google.
Beyond just file size, minified code parses faster in the browser. Before executing JavaScript, the browser must parse the text into an Abstract Syntax Tree (AST). Code with fewer characters and shorter variable names takes less CPU time to parse and compile, leading to faster Time to Interactive (TTI). While server-side compression (Gzip/Brotli) helps with transfer size, minification provides the additional benefit of reduced parsing overhead that compression alone cannot achieve.
Beautification Adjustments
When beautifying JavaScript code, the following adjustments are applied to improve readability:
- Adds proper indentation based on nesting level (configurable: 2 spaces, 4 spaces, or tabs)
- Inserts line breaks after statements, function declarations, and block delimiters
- Adds spacing around operators, keywords, and after commas
- Preserves code logic and functionality while improving readability
Minification Adjustments
When minifying JavaScript code, the following optimizations are performed:
- Removes all unnecessary whitespace, newlines, and indentation
- Removes comments (single-line and multi-line)
- Removes unnecessary semicolons, brackets, and parentheses
- Optimizes boolean expressions and simplifies logic where possible
- Compresses code while maintaining identical functionality
Estimated File Size Impact
Here's what you can expect in terms of file size changes:
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