who is cheaper to mail packages depends on various factors, including the size, weight, and destination of the package. USPS is generally considered cheaper for small, lightweight packages, especially for domestic shipments. For larger packages or expedited shipping, UPS may offer better rates. FedEx also offers competitive pricing, especially for international shipments. To determine the cheapest option, it’s essential to compare rates using each carrier’s online tools or request quotes based on your specific shipment details.