Developer Tools
JavaScript Beautifier & Minifier
Beautify or minify JavaScript online. Format messy JS with consistent indentation and spacing, or strip comments and whitespace for production - all in your browser.
What is JavaScript beautifying?
Minified or machine-generated JavaScript is intentionally hard to read: no indentation, no line breaks, single-character variable names. Beautifying restores consistent indentation, spacing around operators, and line breaks after statements so the code can be reviewed, debugged, or understood.
What is JavaScript minification?
Minification removes comments and collapses whitespace to reduce file size. This tool implements a basic, string-aware minifier suitable for quick transformations. For production builds with dead-code elimination and variable mangling, use a dedicated build tool like terser, esbuild, or your framework's built-in bundler.
When to use each mode
Use Beautify when reading or reviewing unfamiliar code, debugging a minified file, or preparing a code snippet for documentation. Use Minify when you need a quick reduction in file size without setting up a full build pipeline.
Linting vs. formatting
These two tools solve different problems:
- Formatters (like Prettier) enforce a consistent code style: indentation, quotes, semicolons, line length. They rewrite code automatically but do not catch logical errors.
- Linters (like ESLint) enforce code quality rules: unused variables, potential bugs, accessibility issues, security patterns. They flag problems but generally do not rewrite code.
In most projects, Prettier handles formatting and ESLint handles everything else. Running Prettier after ESLint ensures consistent style without fighting ESLint's formatting rules.
Minification for production
This tool's minifier is suitable for quick experiments. For production deployments, use a dedicated build tool:
- esbuild: extremely fast, supports tree-shaking and bundling
- terser: battle-tested JS minifier with advanced dead-code elimination and variable mangling
- Rollup / Vite / webpack: full build pipelines with code splitting, tree-shaking, and source maps
Build tools can reduce production bundles by 60–80% compared to the original source through minification combined with tree-shaking.