Most free minifiers use naive regex and risk corrupting your code. This one uses a real parser — with a safe fallback if the CDN library can't load.
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Real AST minification
Powered by Terser, the same engine behind webpack and Vite, not fragile regex find-and-replace.
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100% client-side
Your code is processed in your browser only. Nothing is uploaded to any server, ever.
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Gzip size estimate
See real-world transfer size, not just raw byte count, using your browser's native compression.
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Safe fallback engine
If Terser can't load, a built-in tokenizer-based minifier takes over automatically — no broken output.
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Minify + Beautify in one tool
Switch between compressing and prettifying minified code without opening a second tool.
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Mangle & compress controls
Toggle variable mangling, console.log stripping, and ES module mode to fit your build pipeline.
A side-by-side look at popular JavaScript minifiers.
Does this JS minifier use real minification or just regex?▾
This tool loads Terser, the same AST-based engine used by webpack and most modern build tools, directly in your browser. If it can't load (for example on a locked-down network), the tool automatically falls back to a safe tokenizer-based engine built into the page, so minification never breaks your code.
Is my JavaScript code uploaded to a server?▾
No. All minification and beautification happens locally in your browser. Your code is never sent to SEOTriggers or any third-party server, unlike tools such as Toptal's JavaScript Minifier which processes code through a server-side API.
What is the difference between minifying and mangling?▾
Minifying removes whitespace, comments, and unnecessary characters. Mangling additionally renames local variables and function parameters to shorter names (like 'a' or 'b'), which reduces file size further but makes stack traces harder to read without a source map.
Why does the tool show a gzip size estimate?▾
Browsers transfer JavaScript over the network compressed with gzip or brotli, so the raw minified size doesn't reflect real-world load time. This tool uses your browser's native compression engine to estimate the gzip size, giving you a more accurate picture of transfer savings.
Can I minify ES6+ syntax like arrow functions and classes?▾
Yes. The Terser engine fully supports ES6 and newer syntax including arrow functions, classes, template literals, destructuring, and async/await. The fallback engine also preserves this syntax safely, though it performs lighter compression.
Will minifying break my JavaScript code?▾
Minification is designed to preserve behavior exactly. The tool parses your code (via Terser or the tokenizer fallback) rather than using naive find-and-replace, so strings, regular expressions, and template literals containing special characters are never corrupted.