USPS First Class vs Priority Mail vs Ground Advantage: 2024 Guide

First-class and priority mail services are both fast mail services supported by the USPS. However, certain advantages make the priority mail service better than the first-class mail service. Below, we have compared the two mail services based on different criteria to arrive at a particular conclusion

Comparing USPS First Class Mail, Priority Mail, and the New USPS Ground Advantage for eCommerce Shipping

The United States Postal Service (USPS) offers various shipping options for eCommerce merchants, including First Class Mail, Priority Mail, and the newly introduced USPS Ground Advantage. In this article, we'll compare these services to help you make an informed decision when choosing the best shipping option for your business.

USPS First Class Mail: Now Limited to Letters and Flats

As of 2023, USPS has made changes to its First Class Mail service. It is now limited to letters, flats, and lightweight envelopes, with packages being shifted to the new USPS Ground Advantage service. First Class Mail remains an affordable option for sending non-package items and is faster than other non-priority mail classes.

USPS Priority Mail: Expedited Shipping for Packages

Priority Mail is an expedited shipping service that allows for the quick transportation of packages weighing up to 70 lbs. Many U.S. shipping companies and eCommerce businesses prefer Priority Mail due to its fast delivery times and ability to handle heavier packages compared to First Class Mail.

USPS Ground Advantage: The New Service for Packages Formerly Sent via First Class Mail

In 2023, USPS introduced Ground Advantage, a new shipping service designed to handle packages that were previously sent using First Class Mail. This service is intended for lightweight packages and offers affordable rates, making it an attractive option for eCommerce merchants shipping small items.

Key Differences Between USPS First Class Mail, Priority Mail, and Ground Advantage

Eligible Items and Weight Limits

  • First Class Mail: Letters, flats, and lightweight envelopes
  • Priority Mail: Packages weighing up to 70 lbs
  • Ground Advantage: Lightweight packages formerly sent via First Class Mail

Delivery Speed

Priority Mail offers the fastest delivery times among the three services, while Ground Advantage and First Class Mail have longer transit times.

  • Domestic Transit Times:
    • First Class Mail: 2-5 days on average
    • Priority Mail: 1-3 days on average
    • Ground Advantage: 2-5 days on average
  • International Transit Times:
    • First Class Mail International: No longer available for packages
    • Priority Mail International: 6-10 days for most major markets
    • Priority Mail Express International: 3-5 days for most major markets
    • Ground Advantage: Domestic service only


Ground Advantage offers competitive rates for lightweight packages, while First Class Mail remains an affordable option for sending letters and flats. Priority Mail is generally more expensive than the other two services but provides faster delivery times and accommodates heavier packages.

Choosing the Right USPS Shipping Service for Your eCommerce Business

When selecting a USPS shipping service, consider the types of items you'll be shipping, their weight, and your delivery speed requirements. If you primarily send letters and flats, First Class Mail is a cost-effective choice. For lightweight packages, Ground Advantage offers competitive rates and reasonable transit times. If you need to ship heavier packages or require faster delivery, Priority Mail is your best option.

By understanding the differences between these USPS shipping services and the recent changes to First Class Mail, you can choose the most suitable option for your eCommerce business, ensuring that you meet customer expectations while managing shipping costs effectively.