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JavaScript Minifier

Compress your JavaScript code with this free minifier.

100% Free No Data Stored Instant

JavaScript Input

Original Size
840 B
Minified Size
561 B
Reduction
33%
279 B saved
Minified JavaScriptjavascript
const API_URL="https://api.example.com";async function getUser(userId){console.log("Fetching user:",userId);const response=await fetch(`${API_URL}/users/${userId}`);if(!response.ok){console.error("Failed to fetch user");throw new Error("Request failed");}const data=await response.json();console.log("User data:",data);return data;}function formatName(first,last){return `${first}${last}`.trim();}document.addEventListener("DOMContentLoaded",()=>{console.log("App initialized");const app=document.getElementById("app");if(app){app.textContent="Hello World";}});
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About This Tool

Compress your JavaScript code with this free minifier. Paste your source code and get a minified version with comments removed, whitespace stripped, and optional console.log statements deleted. The result is smaller, faster-loading JavaScript ready for production deployment. This tool performs basic but effective minification: comment removal, whitespace collapsing, and operator spacing cleanup. It does not rename variables or restructure code, which means the output is still readable when formatted and safe to use even in contexts where obfuscation would break functionality. Size statistics show exactly how many bytes you save. Copy the compressed output directly or download it as a .min.js file. All processing runs on your device with no code sent to any server, keeping your source code private.

What JavaScript Minification Removes

This minifier targets three categories of non-functional code that increase file size without affecting execution:

  • Multi-line comments (/* ... */): JSDoc blocks, license headers, and explanatory notes are removed. These are valuable during development but unnecessary in production.
  • Single-line comments (// ...): Inline notes and TODO markers are stripped. The parser is string-aware, so comment-like characters inside strings (single quotes, double quotes, and template literals) are preserved.
  • Whitespace: Extra spaces, tabs, and blank lines are collapsed. Spaces around operators, braces, parentheses, and semicolons are removed where safe.

The optional "Remove console.log" feature deletes console.log(), console.warn(), console.error(), console.info(), and console.debug() calls. This is useful for production builds where logging should not appear in the browser console.

Basic vs. Advanced Minification

JavaScript minification exists on a spectrum from basic (this tool) to advanced (Terser, UglifyJS, Closure Compiler):

  • Basic minification removes comments and whitespace. The code structure and variable names remain unchanged. This is safe for all code and easy to reverse with a formatter.
  • Advanced minification renames local variables to shorter names (like a, b, c), removes dead code, inlines simple functions, and performs tree-shaking. This produces smaller files but requires a full JavaScript parser and can break code that relies on function name reflection or dynamic property access.

Basic minification typically reduces file size by 20-40%. Advanced minification can achieve 50-70% reduction. For quick tasks, pasting code into this tool gives instant results. For build pipelines, integrate Terser or esbuild into your bundler for maximum compression with variable renaming.

When to Remove Console Statements

Console statements are a common debugging tool, but they should be removed from production code for several reasons:

  • Performance: Each console call has overhead, especially console.log with large objects. In tight loops, this overhead adds up.
  • Security: Logging sensitive data (API keys, user tokens, internal state) to the console exposes it to anyone who opens dev tools.
  • Professionalism: A clean browser console signals attention to detail. Leftover debug logs suggest unfinished development.
  • File size: In verbose applications, console statements and their string arguments can account for several kilobytes of code.

Enable the "Remove console.log" checkbox to strip all five console methods. The removal handles nested parentheses and multi-line calls correctly.

Integrating Minification Into Your Workflow

For ongoing projects, automate minification as part of your build process:

  • Webpack: The TerserWebpackPlugin runs automatically in production mode. No extra configuration needed for basic setups.
  • Vite: Uses esbuild for minification by default. Extremely fast, handles both JavaScript and CSS.
  • Rollup: The @rollup/plugin-terser plugin minifies output bundles. Works with tree-shaking for maximum reduction.
  • npm scripts: Add a minify step to package.json that runs after your build: "postbuild": "terser dist/app.js -o dist/app.min.js"

For one-off tasks like minifying a standalone script, a CDN snippet, or a quick prototype, this online tool provides instant results without installing anything. Paste, minify, copy, and deploy.

Frequently Asked Questions

Does minifying JavaScript change how the code works?
No. This tool only removes comments, whitespace, and optionally console statements. It does not rename variables, change logic, or restructure code. The minified output executes identically to the original in every browser and runtime environment.
How much smaller will my JavaScript file be?
Basic minification (comments and whitespace removal) typically reduces file size by 20-40%. Files with extensive comments and generous formatting see the largest savings. Already compact code may only shrink by 10-15%. The tool shows exact before-and-after sizes so you can measure the improvement.
Will this break my code if I use template literals?
No. The comment removal parser is string-aware. It recognizes double-quoted strings, single-quoted strings, and template literals (backtick strings). Comment-like sequences inside strings are preserved. However, very unusual code patterns with nested template expressions may occasionally need manual verification.
Can I reverse minified JavaScript back to readable code?
Since this tool does not rename variables, you can use any code formatter (Prettier, js-beautify, or your IDE built-in formatter) to re-add whitespace and indentation. The only unrecoverable changes are removed comments. Advanced minifiers that rename variables are much harder to reverse.
Should I minify JavaScript for Node.js server applications?
Generally no. Server-side code is not transferred over the network, so file size does not affect performance. Keep server code readable for debugging. Minification primarily benefits front-end code that browsers must download. The exception is serverless functions where deployment package size affects cold start time.
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Reviewed by the UtilHQ Team

Our tools are verified for accuracy. Results are estimates for planning purposes.