CSS / HTML / JS Code Minifier

Remove comments, collapse whitespace, strip redundant semicolons. See exact byte savings with a size comparison chart.

Minified output







Size comparison








What Minification Does


Minification removes everything that has no runtime effect: comments, unnecessary whitespace, and often optional syntax like trailing semicolons. It's the fastest performance win in any front-end stack — often 20–60% smaller files with zero functionality change.


What This Tool Removes


    

  • HTML — comments, whitespace between tags, redundant spaces in attribute values.
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  • CSS — comments, whitespace, last semicolons in rule blocks, leading zeros on decimals.
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  • JS — comments and whitespace (with full string-literal safety: single, double and template quotes are preserved exactly). Variable renaming is not performed — that requires a real minifier like Terser.
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What Minification Won't Do


    

  • Rename variables (requires AST parsing)
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  • Tree-shake unused code
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  • Dead-code eliminate
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  • Transform or transpile
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  • Resolve CSS duplicate rules
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For production builds, use the real tooling — Terser for JS, cssnano for CSS, html-minifier-terser for HTML. This tool is for quick one-off minification and byte-savings estimation.


Compression vs Minification


Minification and gzip/brotli compression are complementary. Minification reduces raw bytes; gzip then compresses the minified output. Always do both — minified + gzipped files are typically 15–25% of original size.


Safety Notes


The JS minifier preserves single-quoted, double-quoted and template-literal strings exactly, including escape sequences. Regex literals are treated as code — for regex-heavy code, manually verify output. Always diff before deploying.














Minifier FAQ


Will minifying break my code?
HTML and CSS: no, if well-formed. JS: the minifier here preserves all string literals safely. Regex-heavy code should be reviewed manually.


How much does minification save?
Typically 20–50% for HTML/CSS, 30–60% for JS. Combined with gzip, files often shrink to 10–20% of original.


Should I minify or gzip?
Both. Minification removes bytes; gzip compresses what's left. Always deploy minified + gzipped assets.


Is this as good as Terser?
No. Terser parses to an AST and renames variables — often 20–30% additional savings. This tool is a quick pass for one-off work.