JavaScript Deobfuscator
Deobfuscate and beautify obfuscated JavaScript code
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.
What Makes This Tool Different
Smart Deobfuscation
We analyze obfuscated patterns and reverse common obfuscation techniques. Variable name mangling, string encoding, control flow flattening – we handle the most common tricks.
Code Beautification
After deobfuscating, we format the code nicely. Proper indentation, line breaks, and structure make it actually readable. No more squinting at minified mess.
File Upload Support
Got a big file? Just upload it. Works with .js and .txt files. No need to copy-paste massive code blocks – just drag and drop or click upload.
Syntax Highlighting
Both input and output get beautiful syntax highlighting. Makes it easier to see what changed and understand the deobfuscated code structure.
Copy & Download
One click to copy the deobfuscated code, or download it as a file. Perfect for saving cleaned-up versions or sharing with your team.
Privacy First
All processing happens right in your browser. Your code never leaves your computer, so sensitive code stays private and secure.
How It Works
Paste or Upload Obfuscated Code
Paste your obfuscated JavaScript into the left editor, or click "Upload" to load a file. You can also click "Sample" to see an example of obfuscated code. The tool accepts any JavaScript code – whether it's minified, obfuscated, or just messy.
Automatic Deobfuscation
The tool analyzes your code and reverses common obfuscation techniques. Variable names get cleaned up, strings get decoded, and the structure becomes readable. The deobfuscated version appears in the right panel automatically.
Review and Use
Review the deobfuscated code in the output panel. Click "Copy" to copy it to your clipboard, or "Download" to save it as a file. The code is now readable and ready for analysis or modification.
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.
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, but variable names might be different from the original (we use generic names). The logic and functionality should be the same, but exact variable names are often lost during obfuscation.
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.
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:
Need to learn more about JavaScript? Check out the comprehensive guide on MDN or the official ECMAScript specification.