Shopify Migration Image Weight: Up to 1.3MB Lighter

    Median homepage image weight fell after every common ecommerce move to Shopify, from 307 KB lighter for stores leaving WooCommerce to 1,330 KB lighter for stores leaving BigCommerce, but added JavaScript meant most stores still got heavier overall.

    Median image vs JavaScript change after moving to Shopify (KB)
    BigCommerce images-1,330 KB
    BigCommerce JS890 KB
    PrestaShop images-1,206 KB
    PrestaShop JS790 KB
    Salesforce Commerce Cloud images-730 KB
    Salesforce Commerce Cloud JS802 KB
    Magento images-628 KB
    Magento JS519 KB
    WooCommerce images-307 KB
    WooCommerce JS875 KB

    Source: PageSpeed Matters. HTTP Archive top 1M monthly crawls, Sept 2024 to Sept 2026, medians per site.

    Negative values are image weight cuts; redesigns are included, so Shopify alone is not the cause.

    Source: Shopify Migration Image Weight: Up to 1.3MB Lighter - PageSpeed Matters