Need a recommendation? Let me know your OpenCart version (3.0.x or 4.x) and I can point you to a tested module.
Seamless Interspire to OpenCart Migration: Why You Need a Dedicated Module interspire to opencart migration module
However, the migration process itself can be a nightmare if done incorrectly. Manually copying products, customers, and order histories is not only tedious but also risks data corruption, broken URLs (SEO disaster), and lost customer passwords. Need a recommendation
Moving from Interspire Shopping Cart to OpenCart is a smart strategic move. OpenCart offers a more modern framework, a larger extension marketplace, and lower long-term hosting costs. broken URLs (SEO disaster)