During rush hour, you can't afford a laggy system. We tested each POS for speed in processing transactions and scanning inventory. Square and Shopify were the fastest, with near-instant card swipes. Lightspeed and Cova were slightly slower but still acceptable. Clover had occasional hiccups, but mostly fine.

Network reliability is crucial. All five offer offline mode, so you can keep selling even if the internet drops. But offline mode varies—Square and Shopify sync automatically when back online, while others require manual reconciliation.