Delete all users from firebase auth console

For the new Firebase update

Try this code for the latest Firebase update. Open the console, paste this code and hit enter!!!

setInterval(() => {
    document.getElementsByClassName('edit-account-button mat-focus-indicator mat-menu-trigger mat-icon-button mat-button-base')[0].click()
    let deleteButtonPosition = document.getElementsByClassName('mat-focus-indicator mat-menu-item ng-star-inserted').length - 1
    document.getElementsByClassName('mat-focus-indicator mat-menu-item ng-star-inserted')[deleteButtonPosition].click()
    document.getElementsByClassName('confirm-button mat-focus-indicator mat-raised-button mat-button-base mat-warn')[0].click()
}, 1000)

Because I'm pretty lazy at clicking buttons and elements in the UI, I set up a small client script:

$('[aria-label="Delete account"]').click()
setTimeout(function () {
   $(".md-raised:contains(Delete)").click()
}, 1000);

You may need to run it multiple times, but it is much better than wasting the time clicking things on the screen manually.

As in updated answer, you can probably use firebase admin tools now, but if you don't want – here is a bit more solid javascript to remove users in the web:

var intervalId;

var clearFunction = function() {
  var size = $('[aria-label="Delete account"]').size()
  if (size == 0) {
    console.log("interval cleared")
    clearInterval(intervalId)
    return
  }
  var index = Math.floor(Math.random() * size)
  $('[aria-label="Delete account"]')[index].click();
  setTimeout(function () {
     $(".md-raised:contains(Delete)").click()
  }, 1000);
};

intervalId = setInterval(clearFunction, 300)

Just run it in developer tools