JavaScript Minifier
Shrink JavaScript by removing unnecessary whitespace, line breaks and comments — without changing what it does. Strings, template literals and regular expressions are preserved verbatim. Runs in your browser; nothing is uploaded.
About this tool
JavaScript Minifier shrinks JavaScript by removing everything that doesn't affect how the code runs — extra whitespace, line breaks and comments — to make files smaller and faster to download.
- Smaller output: collapses indentation and unnecessary spaces, drops blank lines, and (by default) strips line and block comments.
- Safe by design: it's token-aware, not a text hack. Strings, template literals and regular expressions are emitted verbatim, identifiers are never renamed, and nothing is reordered or dropped — so the minified code is semantically identical to the input.
- ASI-aware: line breaks that matter for automatic semicolon insertion (for
example right after
return) are preserved, so meaning never changes. - Remove comments can be turned off if you want to keep license headers or inline notes.
Everything runs locally in your browser via WebAssembly — your code is never uploaded.
Handy for
- Shrinking a hand-written script before shipping it to production.
- Quickly compressing a snippet to paste somewhere with a size limit.
- Stripping comments and whitespace from a config or vendor file.
FAQ
Does it rename variables like Terser or UglifyJS?
No. This is a token-aware whitespace/comment minifier, not a name-mangler: identifiers are never renamed, and no code is reordered or dropped. The output is a bit larger than a mangling minifier would produce, but it is guaranteed to behave identically to the input — which is the point for hand-checked scripts and vendor files.
How do I keep a license or copyright banner?
Banners survive comment removal automatically: any /*! … */ block comment,
or one containing @license or @preserve, is treated as important and kept
even when "Remove comments" is on. Untick "Keep license/banner comments" if
you really do want every comment stripped.
Can removing line breaks break code that relies on ASI?
No. The minifier knows which source line breaks are significant for
automatic semicolon insertion — for example the one right after a bare
return — and emits those as real newlines instead of collapsing them, so
the program's meaning never changes.
Why did a division sign end up with a space around it?
To keep tokens unambiguous: a / b can't be joined into a/b when the next
character would form // or /*, and a / after certain tokens would start
a regex literal. The minifier inserts the minimum whitespace needed to keep
every token meaning what it did before.
Developer & Automation Access
Run it from the terminal
Same engine as this page, headless — via the gizza CLI:
gizza tool js-minify "function f() {
return a ? 1 : 2;
}"New to the CLI? Get gizza →
Open it by URL
Pre-fill and auto-run this tool with query parameters — the names match the API/CLI:
https://gizza.ai/tools/js-minify/?code=function%20f%28%29%20%7B%0A%20%20return%20a%20%3F%201%20%3A%202%3B%0A%7D&remove_comments=true&keep_license=trueMachine-readable descriptor: tool.json — title + parameters JSON Schema for agents.