Get Placeholder image url in Magento 2.

Native Magento 2 has four types of placeholder image called, small_image, image, thumbnail, and swatch_image.

Placeholder image URL used when you want to display default images for a site.
Magento 2 get placeholder image URL using below simple code snippet.

I hope you are aware of, How to upload Placeholder images in Magento 2?

Create Block file to programmatically get placeholder image,

namespace Rbj\Training\Block;

class Placeholder extends \Magento\Framework\View\Element\Template
    public function __construct(
        \Magento\Framework\View\Element\Template\Context $context,
        \Magento\Framework\View\Asset\Repository $assetRepos,
        \Magento\Catalog\Helper\ImageFactory $helperImageFactory,
        array $data = []
    ) {
        $this->assetRepos = $assetRepos;
        $this->helperImageFactory = $helperImageFactory;
        parent::__construct($context, $data);

     * Get place holder image of a product for small_image
     * @return string
    public function getPlaceHolderImage()
        $imagePlaceholder = $this->helperImageFactory->create();
        return $this->assetRepos->getUrl($imagePlaceholder->getPlaceholder('small_image'));

Call Placeholder function from Template file by below way,

$placeholderUrl = $block->getPlaceHolderImage();
<img src="<?php echo $placeholderUrl; ?>" alt="placeholder" />

Using the above way, You can get small_image Placeholder image url in Magento 2.
You can pass small_image, image, thumbnail and swatch_image for a placeholder.