Comparing object_sizeof and JSON.stringify

result.txt

npm: 34ms
json: 7ms
317780 307781

test.js

var object_sizeof = require("object-sizeof");

var obj = {};
for(var i = 0; i < 10000; i++) {
	obj[i] = {
		i : i,
		data : "aaa"
	}
}

console.time("npm");
var first = object_sizeof(obj);
console.timeEnd("npm");

console.time("json");
var second = JSON.stringify(obj).length;
console.timeEnd("json");

console.log(first, second);