Input

Deobfuscated Output

What is JavaScript Deobfuscator?

Ever come across JavaScript code that looks like it was written by aliens? Variables named `_0x1a2b`, functions wrapped in weird patterns, and code that's impossible to read? That's obfuscated JavaScript – code that's been intentionally scrambled to hide what it does. This tool reverses that process, making obfuscated code readable again.

According to MDN Web Docs, JavaScript is one of the core technologies of the web. Sometimes code gets obfuscated for protection, sometimes it's malicious, and sometimes it's just legacy code that needs to be understood. Our deobfuscator helps you make sense of it all.

The best part? Everything runs right in your browser. Your code never leaves your computer unless you explicitly share it. It's fast, free, and private. You can find many JavaScript libraries on npm and explore open-source deobfuscation tools on GitHub.

How to Use the JavaScript Deobfuscator

Follow these steps to deobfuscate JavaScript. Each step uses the actual buttons and panels on this page.

Paste, Upload, or Load Sample

Paste obfuscated JavaScript into the left panel, or click Upload to load a file. Click Sample to see example obfuscated code. Works with minified, obfuscated, or messy JavaScript.

View Deobfuscated Output

The right panel shows the cleaned-up code. Variable names are restored, strings decoded, structure formatted. Output is readable and ready for analysis.

Copy or Download

Click Copy to copy to clipboard, or Download to save as .js. Use Clear to start fresh. All processing runs in your browser.

When You'd Actually Use This

Security Analysis

Analyzing suspicious JavaScript code? Deobfuscate it to understand what it actually does. Great for security researchers, malware analysts, or anyone trying to figure out if code is safe to run.

Legacy Code Maintenance

Working with old obfuscated code that needs updates? Deobfuscate it first to understand what it does, then make your changes. Much easier than trying to debug obfuscated code.

Learning and Education

Want to understand obfuscation techniques? See how code gets scrambled and how it can be reversed. Great for learning about JavaScript internals and code protection methods.

Code Review

Reviewing third-party libraries or scripts? If they're obfuscated, deobfuscate them first to see what they're actually doing. Helps you make informed decisions about using them.

Common Questions

Is my code stored?

Nope. All deobfuscation happens right in your browser using JavaScript. Your code never leaves your computer – we don't even see it. Check out the ECMAScript for more details.

Can it deobfuscate all types of obfuscation?

We handle the most common obfuscation techniques like variable name mangling, string encoding, and basic control flow changes. Really advanced obfuscation with custom techniques might not be fully reversible, but we'll do our best to make it readable.

Is deobfuscated code exactly the same as original?

Not always. We restore readability following deobfuscation principles, but variable names might differ from the original JavaScript. The logic and functionality remain the same per ECMAScript standards.

Can I use this for malicious code?

This tool is for legitimate purposes like security analysis, code maintenance, and learning. Always use it responsibly and in accordance with applicable laws and terms of service. Read more about software obfuscation on Wikipedia.

How big can my file be?

Since processing happens in your browser, performance depends on your device. Small files deobfuscate instantly. Very large files (several MB) might take a few seconds, but they'll still work.

Does it work with minified code?

Yes, but minified code is different from obfuscated code. Minified code is just compressed – we can format it nicely. Obfuscated code is intentionally scrambled – we reverse those transformations. Both work, but obfuscated code benefits more from deobfuscation.

Other JavaScript Tools You Might Need

Deobfuscation is just one JavaScript task. Here are other tools that work well together: