Minify JavaScript to reduce file size, or beautify minified JS back into readable, indented code.
This performs safe, conservative minification — removing comments and whitespace without renaming variables. For maximum compression in production builds, a full build-tool minifier like Terser or esbuild is recommended.
No, this tool only removes comments and unnecessary whitespace, keeping all variable and function names unchanged for safety and easier debugging.
Yes, use the Beautify button to reformat minified or compressed JS with proper indentation for readability.
No, minification and beautification both run locally in your browser using JavaScript. Your code is never transmitted to a server.
Yes, the minifier tracks string boundaries (single quotes, double quotes, and template literals) so content inside strings is never altered, even if it contains characters that look like code syntax.
Variable renaming requires parsing the full syntax tree to safely track every reference to a name, which is a complex operation beyond what a lightweight browser-based tool can safely guarantee. This tool sticks to comment and whitespace removal, which is always safe regardless of code structure.
No, since only comments and insignificant whitespace are removed, the parsed logic, variable scoping, and runtime behavior of your script stay completely identical before and after minification.
Yes, since the minifier works at the character and string-boundary level rather than parsing language-specific syntax, modern features like arrow functions, template literals, destructuring, and async/await all pass through safely.
This tool compresses JavaScript code by removing comments and unnecessary whitespace to reduce file size, or reformats minified JavaScript back into readable, indented code. It performs safe, conservative transformations without renaming variables or restructuring logic.
This minifier removes comments and collapses whitespace to reduce file size while keeping your code's structure, variable names, and logic completely intact — a safe, predictable transformation that's easy to verify and debug if something looks wrong. It does not perform variable renaming, dead-code elimination, or other advanced optimizations that full build-tool minifiers like Terser, UglifyJS, or esbuild apply. Those tools parse JavaScript into a full syntax tree and can achieve significantly smaller output, but require a build pipeline rather than working as a simple paste-and-convert browser tool. For quick, safe compression of a script without a build process, this tool's conservative approach is a practical middle ground.
A naive minifier that simply strips anything after "//" or collapses all whitespace would break code the moment a string contains those same characters — for example, a URL like "http://example.com" inside a string would be mistaken for the start of a comment. This tool tracks whether each character is currently inside a string literal (single-quoted, double-quoted, or template literal) before applying any comment-stripping or whitespace rules, so content inside strings — including URLs, file paths, and any text that happens to resemble code syntax — passes through completely untouched.
Production JavaScript build pipelines typically use tools like Terser or esbuild, which parse code into a full abstract syntax tree and apply aggressive optimizations: renaming local variables to single letters, eliminating unreachable code, and restructuring expressions for maximum compactness. These tools achieve significantly smaller output than comment-and-whitespace removal alone, but they require a build step and can occasionally introduce subtle bugs if the code relies on function or variable names being preserved (for example, in certain reflection-based patterns). This tool's conservative approach — stripping only comments and whitespace while leaving every name and expression untouched — trades some additional compression for near-zero risk of altering behavior, making it well suited for quickly compressing a standalone script without setting up a full build pipeline, testing framework, or package manager configuration.
For a small utility script, a one-off browser snippet, or sharing compact code without a build process, this tool's safe transformation is often all that's needed. For a production web application serving significant traffic, where every additional kilobyte of JavaScript affects load time at scale, investing in a proper build pipeline with Terser or esbuild is worth the setup effort, since the additional compression from variable renaming and dead-code elimination compounds meaningfully across a large codebase and directly affects how quickly a page becomes interactive for every visitor.
All processing happens directly in your browser — your JavaScript code is never sent to a server, logged, or stored anywhere. This makes the tool safe to use with proprietary scripts or unpublished code, since nothing leaves your own device during minification or beautification.
It's a common situation: you've found a useful but undocumented minified script and need to understand what it does before using it, or you're inspecting a third-party library's bundled output while debugging an integration issue. Pasting minified code into the Beautify function restores readable line breaks and indentation, making it far easier to visually trace function boundaries, conditionals, and loops — even though variable names remain whatever they were in the minified version, since beautifying only restores formatting, not the original descriptive names that may have been stripped by a more aggressive minifier upstream.