JavaScript Obfuscator
Obfuscate JavaScript to protect client-side code from reverse engineering.
Input
Obfuscated Output
What Is the JavaScript Obfuscator?
You've shipped JavaScript to production — and the moment it lands in a browser, anyone can open DevTools and read it. If your client-side code contains proprietary algorithms, licensing checks, or logic you'd rather not hand to competitors on a plate, obfuscation adds a real deterrent. The MDN JavaScript docs explain the language internals that obfuscators exploit. This tool mangles variable names, encodes string literals, and shuffles control flow so the output is functionally identical but deeply unreadable — guided by the ECMAScript spec. For a professional-grade obfuscation pipeline, see obfuscator.io. Here, everything runs in your browser — nothing is sent to a server, so your proprietary code never leaves your machine.
This tool runs entirely in your browser. Nothing is sent to a server. Paste JS or upload a file; get obfuscated output. For deobfuscating, use JavaScript Deobfuscator. For minifying only, use JavaScript Minifier. For formatting, use JavaScript Formatter.
How to Use This Tool
Paste or Upload
Paste JavaScript into the left panel or upload a .js or .txt file. Use Sample to load example code. Use Clear to reset.
View Obfuscated Output
The right panel shows obfuscated code. The logic is preserved but the code is harder to read and reverse.
Copy or Download
Use Copy or Download to get the obfuscated code. Test it before deploying. Obfuscation can affect performance.
JavaScript Obfuscator Examples
Here is an example of obfuscating JavaScript (variable names are mangled).
Example: MSISDN validation
Input (readable):
Obfuscated output (names mangled):
When the JavaScript Obfuscator Helps
When you need to protect client-side logic, hide algorithms, or discourage casual copying, obfuscation adds a layer of difficulty. It is not security; determined users can still reverse it. For size reduction, use JavaScript Minifier. Build tools like webpack and rollup can bundle obfuscated code. See source maps for debugging.
Frequently Asked Questions
Is my JavaScript source code private when I use this?
Yes — obfuscation runs entirely in your browser. Nothing leaves your machine. Safe for proprietary algorithms, licensing logic, and production code.
Does obfuscation break the code?
Good obfuscation preserves runtime behavior. Test the obfuscated output before deploying. Code that uses eval, Function(), or relies on stack trace strings may behave differently.
Can someone reverse the obfuscation?
Yes — obfuscation raises the bar, it doesn't raise a wall. A determined analyst can still reverse it. Use JavaScript Deobfuscator to test how much of your code survives reversal.
What's the difference between obfuscating and minifying?
Minification shrinks code by removing whitespace and shortening names. Obfuscation makes code deliberately unreadable with encoding and control flow transformations. Obfuscated output is usually larger than the original.
Does obfuscation slow down my JavaScript?
Heavy obfuscation (especially control flow flattening) can measurably slow execution. Use moderate settings for production and always benchmark. The source map won't help you debug obfuscated code — keep the original.