Shrink JavaScript with a real parser, not regex.
Paste JavaScript and get a smaller file that behaves the same. The minifier parses your code properly (it uses Terser), so it can remove dead code, shorten expressions and rename local variables safely, which regex-based minifiers cannot do. Everything runs in your browser; your code is not uploaded.
Will minified code still work?
Yes. Minifying removes whitespace and comments and rewrites expressions into shorter equivalents. Mangling renames local variables only, never globals or property names, so the behaviour stays the same.
Is my code uploaded?
No. The minifier is loaded into your browser and runs there.
JavaScript Minifier runs in your browser, so there is no server call for it. API docs covers the tools you can call from code.