JavaScript Minifier

A JavaScript minifier compresses source code into the smallest equivalent form by removing whitespace and comments, and optionally renaming local variables to shorter identifiers. JavaScript is one of the heaviest resources on most pages, and because it has to be downloaded, parsed, and executed before the page becomes interactive, cutting its size directly improves load and interaction times. This tool strips spaces, line breaks, and comments, and offers an optional name-mangling pass that shortens local variable and function names to single characters for additional savings. Mangling is off by default and only touches local names; it deliberately leaves global names and exports alone so it does not break references that other scripts rely on. As a rough guide, whitespace and comment removal alone typically cuts 30 to 60 percent, and enabling mangling can push that to roughly 50 to 70 percent depending on how the code is structured. The tool displays the original size, the minified size, and the percentage saved. A few honest caveats. Minification preserves behavior, but it is not the same as the advanced dead-code elimination and tree-shaking that a bundler like esbuild, Terser, or Rollup performs across an entire dependency graph. This is a single-file, paste-and-go minifier, ideal when you need a quick production version of a script and do not have a build pipeline running. It supports ES6+ syntax including arrow functions, template literals, async and await, and modules, though some constructs such as dynamic imports may not compress as fully. Because it runs entirely in your browser, your source never leaves your device, which matters for proprietary code. For the reverse, the JavaScript Beautifier expands minified code back into readable form, although it cannot recover names that mangling already discarded.