JS Minify & Compress
Minify JavaScript code instantly. Reduce JS file size up to 70%, supports ES5, ES6, ES2015+ and modern JavaScript. Remove comments, whitespace, and optimize your scripts.
Why Use JS Minify?
Professional JavaScript compression with precise options for modern ES6+ codebases and production deployments.
Comment Removal
Strips all single-line // and block /* */ comments from your JavaScript, including JSDoc comments and inline annotations.
Whitespace Compression
Collapses tabs, spaces, and newlines. Preserves necessary whitespace inside strings and template literals so functionality is never broken.
Console Statement Removal
Removes all console.log, .warn, .error, and .info calls that should not appear in production code.
Numeric Literal Optimization
Shortens numeric literals for smaller output. 0.5 becomes .5, 1000 becomes 1e3, and trailing zeros are removed.
Boolean Compression
Converts boolean literals to their shortest equivalents. true becomes !0 and false becomes !1, saving 2–3 bytes per occurrence.
Debugger Removal
Automatically strips all debugger; statements that developers leave in code during development to prevent breakpoints in production.
ES5, ES6, ES2015+ Support
Full support for modern JavaScript syntax including arrow functions, template literals, destructuring, async/await, optional chaining, and nullish coalescing.
100% Browser-Side
All minification happens entirely in your browser. Your JavaScript source code is never uploaded to any server — completely safe for proprietary or confidential code.
Minify JavaScript in 5 Steps
Compress your JavaScript instantly with no installation, no registration, and no server uploads required.
Paste Your JavaScript
Copy your JS source code from your editor or file and paste it into the JavaScript Source Code input area above.
Choose Core Options
Select which elements to remove: comments, whitespace, console statements, and debugger statements are all on by default.
Enable Advanced Options
Click "Show advanced options" to enable boolean compression, numeric optimization, undefined compression, and other power-user features.
Click Minify JavaScript
Press the Minify JavaScript button to instantly compress your code. Processing happens client-side in milliseconds with no data leaving your browser.
Copy & Deploy
Use the Copy JS button to copy the minified output to your clipboard, then paste it into your production JavaScript file or bundle.
JavaScript Minifier & Compressor — Optimize Your JS Code
JS Minify is a free, fast, and reliable online tool for compressing and minifying JavaScript code. Whether you're building a personal project, a React application, a Node.js backend, or a large enterprise web platform, reducing JavaScript file size is one of the most impactful performance optimizations you can make.
What is JavaScript Minification?
JavaScript minification is the process of removing all unnecessary characters from JS source code without changing its functionality. Unnecessary characters include whitespace (spaces, tabs, newlines), comments, and in some cases renaming variables to shorter names. A well-minified JavaScript file can be 30–70% smaller than the original, dramatically reducing the amount of data browsers need to download, parse, and execute.
Tools like Google Lighthouse, PageSpeed Insights, and GTmetrix all flag unminified JavaScript as a performance bottleneck. Using JS Minify ensures your scripts are deployment-ready and pass web performance audits.
JS Minifier Options
JS Minify supports both core and advanced minification options for complete control over your output:
- Remove // and /* */ comments
- Collapse whitespace and newlines
- Remove console.log / .warn / .error
- Remove debugger statements
- true → !0, false → !1 compression
- undefined → void 0 compression
- Infinity → 1/0 compression
- 0.5 → .5 numeric optimization
- 1000 → 1e3 scientific notation
- Add timestamp comment header
- Remove optional semicolons
- Merge adjacent string literals
ES6 and Modern JavaScript
JS Minify is fully compatible with modern JavaScript syntax. Arrow functions, template literals, destructuring assignments, default parameters, rest/spread operators, async/await, optional chaining (?.), nullish coalescing (??), class declarations, and module syntax (import/export) are all handled correctly without breaking your code.
Best Practices for JavaScript Minification
Always keep your original, unminified source files in version control. Deploy only the minified version to production. For larger projects, consider integrating minification into your build pipeline using tools like webpack, Rollup, Vite, or esbuild, which handle minification automatically during the build process. Use JS Minify for quick, one-off compression tasks or when working outside of a build tool context.
Privacy and Security
All JavaScript processing with JS Minify happens entirely in your browser. Your code is never transmitted to any server, never logged, and never stored. You can safely use this tool with proprietary, closed-source, or commercially sensitive JavaScript code, including API keys, business logic, and internal tools.
Frequently Asked Questions
Common questions about JavaScript minification, compression, and using the JS Minify tool.
JavaScript minification is the process of removing unnecessary characters from JS source code without changing its functionality. This includes removing whitespace, line breaks, comments, and optionally shortening variable names to reduce file size and improve website loading speed. The resulting code is functionally identical but occupies significantly less storage and network bandwidth.
JS Minify typically reduces JavaScript file size by 30–70% depending on the original code. Files with many comments, long descriptive variable names, and verbose whitespace see the greatest reduction. Enabling all advanced options like boolean compression and numeric optimization maximizes size savings.
Yes! JS Minify supports ES5, ES6/ES2015, ES2016, ES2017, ES2018, ES2019, ES2020 and newer JavaScript syntax. This includes arrow functions, template literals, destructuring, classes, async/await, optional chaining (?.), nullish coalescing (??), and all other modern JavaScript features. The tool handles these correctly without breaking syntax.
Yes, basic JS minification (removing comments and whitespace) is completely safe. Always keep your original unminified source files in version control as a backup. When using advanced options like removing console statements or compressing booleans, it's good practice to run your test suite on the minified output before deploying to production.
Minification removes unnecessary characters (whitespace, comments) to reduce file size while preserving functionality and human readability of identifiers. Obfuscation intentionally transforms code to make it difficult to understand, often renaming variables to single characters or meaningless names. JS Minify focuses on minification for performance — not obfuscation for security. Note that obfuscation does not provide true security as determined parties can always reverse-engineer client-side JavaScript.
The boolean compression option converts true to !0 (NOT zero, which evaluates to true) and false to !1 (NOT one, which evaluates to false). This saves 2 bytes for true and 3 bytes for false on each occurrence. In a file with many boolean values, the savings add up quickly.
Minifying JavaScript is a best practice for any production website or web app. Smaller files download faster, parse faster, and execute faster — improving Core Web Vitals, especially Largest Contentful Paint (LCP) and Time to Interactive (TTI). For development, keep your original readable source. For production, always serve minified files. Google PageSpeed Insights and Lighthouse both recommend JavaScript minification.
Absolutely. JS Minify processes all JavaScript entirely in your browser using client-side JavaScript. Your code is never uploaded to any server, never logged, and never stored anywhere. You can safely use this tool with proprietary code, API integrations, or any confidential JavaScript. The tool continues to function even if you disconnect from the internet after the page loads.