How to Minify JavaScript
JavaScript Minification
When to Minify JavaScript
Compress scripts for production bundles, compare minified output sizes, or inspect how whitespace removal affects code length before deploying static assets or embeddable widgets.
What Minify Does
Removes comments and unnecessary whitespace. Variable names are not mangled and compress optimizations are disabled, so output stays closer to the source than production minifiers.
Common Mistakes
- Expecting minify to fix syntax errors — invalid code will fail
- Running untrusted minified output without reviewing it first
- Assuming minified size equals gzip size — always measure compressed bytes
Frequently asked questions
Is minified output safe to run?
Minified code is still executable JavaScript. Only run output you trust, same as any source code.
Why are variable names preserved?
Preserving names keeps minified output easier to debug than production builds that mangle identifiers.