I would like to perform migration from Summer Cart to Magento. Will my old URLs will be transferred to a target cart without losing my positions on Google?

Unfortunately, for now it isn't possible to migrate SEO URLs from Summer Cart to Magento. Cart2Cart supports migration of SEO for Magento, OpenCart, CS-Cart, PrestaShop, PrestaShop Cloud, WooCommerce, Virtuemart 2.x, Shopify, WP eCommerce, Bigcommerce, AceShop, MijoShop, X-Cart, osCommerce, Jigoshop, ePages. However, you will be able to configure it after transferring completion. Check our article for more details.