ShipEngine

ShipEngine provides a unified shipping API that connects sellers to multiple carriers through a single integration. The platform supports USPS, UPS, FedEx, DHL, and dozens of regional carriers, letting sellers compare rates across all options and choose the most cost-effective service for each shipment.

The API-first approach makes ShipEngine popular among sellers and developers building custom shipping workflows. Rate shopping compares prices across carriers in real time, factoring in package dimensions, weight, and destination. Address validation catches errors before labels are printed, reducing undeliverable packages and associated costs.

For sellers with custom-built systems or unique shipping requirements, ShipEngine offers the flexibility that pre-built shipping platforms may not provide. The pay-per-label pricing model means sellers only pay for what they use, making it cost-effective for businesses of any size. The robust documentation and developer tools make integration straightforward for technical teams.