JavaScript Minifier
Minify JavaScript code to reduce size.
Minify JavaScript code to reduce size.
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Tool guide
Free Online JavaScript Minifier
Minify JavaScript by removing common comments, collapsing whitespace, and tightening spaces around punctuation. This lightweight browser tool can reduce simple JS text, but it is not a parser-based production optimizer or a replacement for Gzip, Brotli, or a build pipeline.
Steps
How it works
- Paste JavaScript or choose one JS, MJS, or TXT file.
- Run the JavaScript minifier in your browser.
- Compare the original and minified byte counts and reported reduction.
- Copy the result or download the minified JS file.
Highlights
Key features
- Removes common block comments and line comments with text rules.
- Collapses repeated whitespace and spaces around common JavaScript punctuation.
- Shows original size, minified size, and percentage reduction.
- Accepts pasted code and supported JavaScript or text files.
- Does not execute the submitted JavaScript.
Use cases
Common uses
- Compact a short JavaScript snippet for a demo.
- Compare readable and reduced versions of simple code.
- Remove basic formatting from small test fixtures.
- Create a quick minified copy for noncritical experiments.
Notes
Limitations to know
- The minifier is regex-based and may alter strings, URLs, regular expressions, template literals, or comment-like text.
- It does not shorten identifiers, fold constants, remove dead code, or tree-shake modules.
- It does not parse JSX or TypeScript and does not generate source maps.
- Comment preservation options, license-comment handling, and advanced compression settings are not available.
- Minified output must be tested before production use and cannot recreate the original formatting.
FAQ
Frequently asked questions
Does minification change JavaScript behavior?
It is intended to remove unnecessary text, but the lightweight rules are not syntax-aware. Always test the generated code.
Are comments removed?
Common block and line comments are removed, although comment-like text in syntax-sensitive contexts may also be affected.
Are variable names shortened?
No. Identifier mangling is not implemented.
Is JavaScript minification the same as Gzip or Brotli?
No. Minification changes source text; Gzip and Brotli are transfer-compression methods normally configured by a server or build process.
Does it remove unused code or tree-shake modules?
No. It performs no dependency analysis, dead-code removal, or tree shaking.
Can minified JavaScript be restored exactly?
No. Removed comments and original whitespace cannot be recovered from the minified output.