Deserialize query string to JSON object

In modern browsers, you can also use Object.fromEntries which makes this even easier.

function queryStringToObject(queryString) {
  const pairs = queryString.substring(1).split('&');
  // → ["foo=bar", "baz=buzz"]

  var array = pairs.map((el) => {
    const parts = el.split('=');
    return parts;
  });
  // → [["foo", "bar"], ["baz", "buzz"]]

  return Object.fromEntries(array);
  // → { "foo": "bar", "baz": "buzz" }
}

console.log(queryStringToObject('?foo=bar&baz=buzz'));

The URLSearchParams interface can Interactive with the browsers URL search parameters. The browser support for URLSearchParams is pretty decent.

For your case, it would be:

console.log(
  Object.fromEntries(new URLSearchParams('foo=bar&baz=buzz'))
);

I am posting here my function just in case other will look and will want to get it straight forward no need for jquery native JS. Because I was looking for the same thing and finally made this function after viewing others answers:

function queryStringToJSON(queryString) {
  if(queryString.indexOf('?') > -1){
    queryString = queryString.split('?')[1];
  }
  var pairs = queryString.split('&');
  var result = {};
  pairs.forEach(function(pair) {
    pair = pair.split('=');
    result[pair[0]] = decodeURIComponent(pair[1] || '');
  });
  return result;
}


console.log(queryStringToJSON(window.location.href)); 
console.log(queryStringToJSON('test=1&check=wow'));//Object {test: "1", check: "wow"}

You have Ben Alman's jQuery BBQ and a jQuery.deparam in it. It is described as The opposite of jQuery.param, pretty much.

http://benalman.com/code/projects/jquery-bbq/examples/deparam/

First example is exactly what you need.

Actually the above answer by @talsibony doesn't take into account query string arrays (such as test=1&test=2&test=3&check=wow&such=doge). This is my implementation:

function queryStringToJSON(qs) {
    qs = qs || location.search.slice(1);

    var pairs = qs.split('&');
    var result = {};
    pairs.forEach(function(p) {
        var pair = p.split('=');
        var key = pair[0];
        var value = decodeURIComponent(pair[1] || '');

        if( result[key] ) {
            if( Object.prototype.toString.call( result[key] ) === '[object Array]' ) {
                result[key].push( value );
            } else {
                result[key] = [ result[key], value ];
            }
        } else {
            result[key] = value;
        }
    });

    return JSON.parse(JSON.stringify(result));
};