JavaScript Obfuscation & Entropy Analyzer
Detect code obfuscation, packed scripts, high Shannon entropy, eval() execution, and suspicious variable patterns in JavaScript.
About This Tool
The JavaScript Obfuscation & Entropy Analyzer scans JavaScript payloads for common malware and packer signatures, including hexadecimal variable arrays (`_0x4f2a`), `eval()` string unpacking, character code manipulation, and high Shannon information entropy.
Key Features
How to Use This Tool
- Paste your suspicious or bundled JavaScript code snippet.
- View the Obfuscation Risk Score and detected heuristic signatures.
- Inspect matched malicious or packed code blocks.
Why Use This Tool
- Audit third-party npm scripts and browser extensions for concealed malicious payloads.
- Check whether your production client bundles are effectively minified vs obfuscated.
Pro Tips
- Normal minified code typically has an entropy of 4.5–5.2, whereas encrypted/obfuscated code often exceeds 5.8.
Frequently Asked Questions
What is Shannon Entropy in source code analysis?
Shannon Entropy measures the randomness of character distribution in a string. Plain code has predictable patterns (lower entropy), while encrypted, packed, or base64-encoded code has high character randomness (high entropy).
Is minified code the same as obfuscated code?
No. Minification only strips whitespace and renames variables to reduce file size. Obfuscation deliberately mangles code logic and string literals to prevent human comprehension and reverse-engineering.
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