A complete platform for shipping packages

Shipping labels, tracking and analytics for
businesses that use Fedex, UPS, USPS, and Regional Carriers.

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Postmaster: developer friendly shipping

Integrate, ship, track, validate and notify.

Print Labels

Print shipping labels for all carriers. Formats include PDF, PNG and thermal (ZPL/EPL).

Print labels »

Save on USPS

Save up to 63% on USPS Priority Mail and Express Mail. Qualifying shippers also get USPS Cubic Pricing and Commercial Plus rates.

Save me money »

Address Validation

Make sure your addresses are going to the right place. Our API can give you insights like latitude/longitude, vacancy, and residential/commercial status.

Validate addresses »

Easy Integration

A simple (RESTful) API with SDKs for Python, iOS, PHP, Ruby, Java and .NET. One API gives you Fedex, UPS, USPS, and Regional Carriers

Library details »


Track packages and notify your customers of shipment events like "out for delivery" and "delivered" by SMS, Email or use our webhook framework.

Track a package »


Not sure which carrier is the best? Let our API automatically pick the best option for you. We'll analyze your package, destination, anticipate accessorials, and save you money.

Use the API »