JS-Confuser vs Obfuscator-LLVM

JS-Confuser obfuscates JavaScript to make source code harder to understand, copy, reuse, or modify while preserving its functionality. Its browser playground accepts pasted code, lets users choose settings, and produces a downloadable result. The playground runs in the browser, including offline, and says it does not send code or actions to a remote server. Users can start with Low, Medium, or High presets or create custom configurations. Options include renaming variables, concealing strings, flattening control flow, inserting dead code, setting domain or date locks, and tamper protection. The API offers JSConfuser.obfuscate for source code and JSConfuser.obfuscateAST for Babel ASTs; output targets include Browser and Node.js. The editor includes Prettier and a JSON representation of JSConfuser.ts settings. JS-Confuser is described by its maker as free and open source. Obfuscation can increase file size and performance overhead or break a program, and it cannot prevent determined reverse engineers from recovering code or sensitive information. Tamper protection requires eval and non-strict mode.

Obfuscator-LLVM is a free, open-source LLVM fork for Linux that applies obfuscation while software is compiled. It is intended to make programs harder to reverse engineer or modify. Listed passes include instruction substitution, bogus control flow, and control-flow flattening, with function annotations also available. Its intermediate-representation approach covers languages supported by LLVM, including C, C++, Objective-C, Ada, and Fortran. Listed targets include x86, x86-64, PowerPC, ARM, Thumb, SPARC, Alpha, CellSPU, MIPS, MSP430, SystemZ, and XCore. Installation involves cloning the source repository, then building with CMake and make; binaries are placed in build/bin. The guide describes compiler use through Clang, autotools, and a custom Xcode plugin. The latest official non-development branch is llvm-4.0, based on LLVM 4.0.1. The project says obfuscated code can be slower and larger, and describes itself as an advanced prototype needing more testing before production use.