Get Instagram Unfollowers: Get a list of people whom you follow but who do not follow you back on Instagram as well as the list of people who follow you but whom you don't follow back!

instagramunfollowers.js

// Gist by acesmndr@gmail.com Rev 2.1.2 May 15, 2019
// go to your insta profile page (not the home page). It looks something like this: https://instagram.com/YOUR_PROFILE
// Open javascript console  "Ctrl + Shift + i" in Windows/Linux and "Cmd + option + i" in Mac.
// Paste the entire code below to the console and hit enter 
// You will get the list of people whom you follow but who don't follow you back and viceversa as well as the entire list of followers and following

var following = [],
  followers = [],
  followersCount = 0,
  followingCount = 0,
  scrolledFollowersCount = 0,
  scrolledFollowingCount = 0,
  hashtagCount,
  scrollingCount = 0; // temp variable to store the count for following and followers while scrolling

function diff(array) {
  return function (current) {
    return array.filter(function (element) {
      return element.userId === current.userId && element.userName == current.userName;
    }).length == 0;
  }
}

function openFollowersDialog(){
  if (!document.querySelector('a[href*="/followers/"]')) {
    console.clear();
    console.error('You are most likely in the homepage and not the profile page. It is the page with your photos only.');
    return;
  }
  followersCount = parseInt(document.querySelector('a[href*="/followers/"]').firstElementChild.textContent);
  document.querySelector('a[href*="/followers/"]').click() // go to Followers
  setTimeout(function(){
    console.clear();
    console.debug(`Please wait...`);
    scrollFollowers();
  },1000);
}

function openFollowingDialog() {
  followingCount = parseInt(document.querySelector('a[href*="/following/"]').firstElementChild.textContent);
  document.querySelector('a[href*="/following/"]').click(); // go to followers
  setTimeout(function () {
    console.clear();
    console.debug(`Please wait...`);
    scrollFollowing();
  }, 2000);
}

function scrollFollowers(){
  var scrollDiv = document.querySelector('div[role="presentation"]').querySelector('li').parentElement;
  scrollDiv.lastElementChild.scrollIntoView();
  console.clear();
  console.debug(`Loaded ${scrollDiv.childElementCount} out of ${followersCount} followers. Please wait...`);
  setTimeout(function(){
    if (scrollDiv.childElementCount === followersCount || (scrollingCount === scrollDiv.childElementCount && (followersCount - scrollingCount) < hashtagCount)) {
      scrolledFollowersCount = scrollDiv.childElementCount;
      getFollowers();
      console.clear();
      console.debug(`Please wait while the following list is loaded...`);
      setTimeout(function(){
        console.clear();
        console.info(`Scroll Followers completed with ${followersCount} people`);
        console.debug(`Please wait...`);
        scrollingCount = 0;
        openFollowingDialog();
      }, 3000);
    } else {
      scrollingCount = scrollDiv.childElementCount; // current count of loaded followers
      scrollFollowers();
    }
  },1000);
}

function scrollFollowing() {
  var scrollDiv = document.querySelector('div[role="presentation"]').querySelector('li').parentElement;
  scrollDiv.lastElementChild.scrollIntoView();
  console.clear();
  console.debug(`Loaded ${scrollDiv.childElementCount} out of ${followingCount} following people. Please wait...`);
  setTimeout(function () {
    if (scrollDiv.childElementCount === followingCount || (scrollingCount === scrollDiv.childElementCount && (followingCount - scrollingCount) < hashtagCount)) {
      scrolledFollowingCount = scrollDiv.childElementCount;
      getFollowing();
      console.info(`Scroll following completed with ${followingCount} people`);
      setTimeout(function () {
        document.querySelector('[aria-label="Close"]').click();
        getResults();
      }, 1000);
    } else {
      scrollingCount = scrollDiv.childElementCount; // current count of loaded following people
      scrollFollowing();
    }
  }, 1000);
}

function getFollowers(){
  var followersDiv = document.querySelector('div[role="presentation"]').querySelector('li').parentElement.children;
  for (var i = 0;i<followersDiv.length;i++){
    var tempUser = followersDiv[i].lastElementChild.children[0].children[1];
    followers.push({
      userID: tempUser.children[0].textContent,
      userName: tempUser.children[1].textContent,
    });
  }
  document.querySelector('[aria-label="Close"]').click();
}

function getFollowing(){
  var followersDiv = document.querySelector('div[role="presentation"]').querySelector('li').parentElement.children;
  for (var i = 0;i<followersDiv.length;i++){
    var tempUser = followersDiv[i].lastElementChild.children[0].children[1];
    following.push({
      userID: tempUser.children[0].textContent,
      userName: tempUser.children[1].textContent,
    });
  }
}

function getResults(){
  console.clear();
  var consoleColors = 'color:#bada55;background:black;font-weight:bold;font-size:20px';
  console.info('The results might shock you! Keep calm!');
  console.log('Your following list:', following);
  console.log('Your followers list:', followers);
  var unfollowing = following.filter(diff(followers));
  console.log(`%c There are ${unfollowing.length} people who you are following but who don\'t follow you. They are:`, consoleColors);
  console.table(unfollowing);
  var unfollowers = followers.filter(diff(following));
  console.log(`%c There are ${unfollowers.length} people who are following you but who you aren\'t following. They are:`, consoleColors);
  console.table(unfollowers);
  console.info(`You have loaded ${scrolledFollowersCount} out of ${followersCount} followers and ${scrolledFollowingCount} out of ${followingCount} of the people you follow.`);
  console.info('If the above numbers differ by a huge amount then you need to run the script again. Don\'t switch to another page while the script is running');
  console.info(`There are hashtags in people you follow. It's based on the assumption that you follow hashtags below 10. If you follow somewhere above 10. then run 'getInstagramStats(20) if you follow 20 hashtags'`);
  console.info(`%c For a social cause: acesmndr@gmail.com`, consoleColors);
}

var getInstagramStats = function(htagCount) {
  if (/(http\:|https\:)\/\/(www.)instagram.com\//.test(location.href)) {
    hashtagCount = htagCount + 1;
    openFollowersDialog();
  } else {
    console.clear();
    console.error('You should be in your instagram profile in order to execute the script');
  }
}
getInstagramStats(10);

Line 30 and 40 breaks if you have more than 1k followers

https://gist.github.com/Acesmndr/eb9fdc42b8fed0416ee658af692adb69#file-instagramunfollowers-js-L30
https://gist.github.com/Acesmndr/eb9fdc42b8fed0416ee658af692adb69#file-instagramunfollowers-js-L40

Ex: for line 40
it should be parseInt(document.querySelector('a[href*="/followers/"]').firstElementChild.textContent.replace(',', ''))

Add .replace(',', '') in line 30 the same way.