0xdevalias

Deobfuscating / Unminifying Obfuscated Web App / JavaScript Code

Table of Contents

• PoC
• Tools
  • Unsorted
• wakaru

tomhicks

/*
Copy this into the console of any web page that is interactive and doesn't
do hard reloads. You will hear your DOM changes as different pitches of
audio.

I have found this interesting for debugging, but also fun to hear web pages
render like UIs do in movies.
*/

const audioCtx = new (window.AudioContext || window.webkitAudioContext)()

paulirish

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.

Element APIs

Getting box metrics

• elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent

yuval-a

NOTE: This document is OLD - and most of the tips here are probably outdated, since newer versions of Javascript have been
released over the years - with newer optimizations and more emphasis on optimizing newly supported syntax.


// Array literal (= []) is faster than Array constructor (new Array())
// http://jsperf.com/new-array-vs-literal/15
var array = [];

// Object literal (={}) is faster than Object constructor (new Object())
// http://jsperf.com/new-array-vs-literal/26