I need to get all the cookies from the browser

You can only access cookies for a specific site. Using document.cookie you will get a list of escaped key=value pairs seperated by a semicolon.

secret=do%20not%20tell%you;last_visit=1225445171794

To simplify the access, you have to parse the string and unescape all entries:

var getCookies = function(){
  var pairs = document.cookie.split(";");
  var cookies = {};
  for (var i=0; i<pairs.length; i++){
    var pair = pairs[i].split("=");
    cookies[(pair[0]+'').trim()] = unescape(pair.slice(1).join('='));
  }
  return cookies;
}

So you might later write:

var myCookies = getCookies();
alert(myCookies.secret); // "do not tell you"

1. You can't see cookies for other sites.
2. You can't see HttpOnly cookies.
3. All the cookies you can see are in the document.cookie property, which contains a semicolon separated list of name=value pairs.

You cannot. By design, for security purpose, you can access only the cookies set by your site. StackOverflow can't see the cookies set by UserVoice nor those set by Amazon.

To retrieve all cookies for the current document open in the browser, you again use the document.cookie property.

Modern approach.

let c = document.cookie.split(";").reduce( (ac, cv, i) => Object.assign(ac, {[cv.split('=')[0]]: cv.split('=')[1]}), {});

console.log(c);

;)

Added trim() to the key in object, and name it str, so it would be more clear that we are dealing with string here.

export const getAllCookies = () => document.cookie.split(';').reduce((ac, str) => Object.assign(ac, {[str.split('=')[0].trim()]: str.split('=')[1]}), {});

If you develop browser extensions you can try browser.cookies.getAll()

What you are asking is possible; but that will only work on a specific browser. You have to develop a browser extension app to achieve this. You can read more about chrome api to understand better. https://developer.chrome.com/extensions/cookies