How to read from Chrome’s console in JavaScript

You can’t. What’s in the console can’t be read from JavaScript.

What you can do is hook the console.log function so that you store when it logs :

console.stdlog = console.log.bind(console);
console.logs = [];
console.log = function(){
    console.logs.push(Array.from(arguments));
    console.stdlog.apply(console, arguments);
}

console.logs contains all what was logged. You can clean it at any time by doing console.logs.length = 0;.

You can still do a standard, non storing, log by calling console.stdlog.