How to get Magento 2 customer group ID

To get logged in customer group id directly in phtml without using Dependency Injection, You can use the object manager to get group id in your phtml file.

<?php
  $objectManager = \Magento\Framework\App\ObjectManager::getInstance();
  $customerSession = $objectManager->create('Magento\Customer\Model\Session');
  if ($customerSession->isLoggedIn()) {
      echo 'Customer Group Id: ' .  $customerSession->getCustomer()->getGroupId();
  }
?>

Using Dependency Injection

app/code/Vendor/Module/Block/CustomBlock.php

<?php
namespace Vendor\Module\Block;
class CustomBlock extends \Magento\Framework\View\Element\Template
{
    protected $_customerSession;

    public function __construct(
        \Magento\Framework\View\Element\Template\Context $context,
        \Magento\Customer\Model\SessionFactory $customerSession,
        array $data = []
    ) {
        $this->_customerSession = $customerSession->create();
        parent::__construct($context, $data);
    }

    public function getCustomerGroupId() {
        if ($this->_customerSession->isLoggedIn()) {
            return $this->_customerSession->getCustomerData()->getGroupId();
        }
        return false;
    }
}

Now, you can use the functions in your phtml file as follows.

<?php $customer= $block->getLayout()->createBlock(‘JJ\LoggedOut\Block\CustomerGroupId’); $group = $customer->getCustomerGroupId();?>