Get is comparable attribute list programmatically in magento 2.

Magento 2 Compare product is one of the native features available with Out of the box. You can compare multiple products from listing and product pages with a click on compare link.

If you want to know about get all the is_comparable attribute lists using programmatically you need to use Magento\Eav\Api\AttributeRepositoryInterface Interface.

Comparable on Storefront Set to Yes used for compare products in a storefront.

I have given a demo using Block file,

<?php
namespace Rbj\Compare\Block;

class Demo extends \Magento\Framework\View\Element\Template
{
    public function __construct(
        \Magento\Framework\View\Element\Template\Context $context,
        \Magento\Framework\Api\SearchCriteriaBuilder $searchCriteriaBuilder,
        \Magento\Eav\Api\AttributeRepositoryInterface $attributeRepository,
        array $data = []
    ) {
        $this->searchCriteriaBuilder = $searchCriteriaBuilder;
        $this->attributeRepository = $attributeRepository;
        parent::__construct($context,$data);
    }

    public function getIsComparableAttribute()
    {
        try {
            $attributeSearchCriteria = $this->searchCriteriaBuilder->create();
            $attributeRepository = $this->attributeRepository->getList(
                'catalog_product',
                $attributeSearchCriteria
            );
            $additionalAttributeCollection = [];
            foreach ($attributeRepository->getItems() as $item) {
                if ($item->getIsComparable()) {
                    $additionalAttributeCollection[] = $item->getAttributeCode();
                }
            }
            return $additionalAttributeCollection;
        } catch (\Exception $exception) {
            throw new \Magento\Framework\Exception\NoSuchEntityException(__('Such Attribute doesn\'t exist'));
        }
        return '';
    }

From template file,

$productComparable = $block->getIsComparableAttribute();
foreach ($productComparable as $value) {
    echo $value;echo "<br>";
}

The result for Magento 2.3 With sample data installed, All is_comparable attribute code,

sku
description
short_description
manufacturer
activity