The USPS API
you wish existed.

Address validation, rate quotes, and shipping intelligence. Free tier, flat pricing, SDKs for Python, Node, and PHP.

No credit card required.

 
api.revaddress.com
200 OK • 42ms
 GET /api/address/validate
// Response
{
  "streetAddress": "1600 PENNSYLVANIA AVE NW",
  "city":          "WASHINGTON",
  "state":         "DC",
  "ZIPCode":       "20500",
  "ZIPPlus4":      "0005",
  "DPVConfirmation": "Y",
  "deliveryPoint": "99",
  "business":      "N",
  "vacant":        "N"
} 
  
DPV Confirmed
 
Residential
 
ZIP+4 Resolved
 

api.revaddress.com — live

Two curl commands. Real API. Real USPS responses.

Try it — validate any address

No signup. No API key. Free tier, live USPS responses.

api.revaddress.com

Free tier: validation, rates, ZIP+4, and address extract. Get an API key for higher limits.

Flat pricing, no per-lookup surcharges

SmartyStreets charges per lookup. EasyPost adds per-label fees. RevAddress is a flat monthly rate — your 1,000th validation costs the same as your first: $0.

See the full comparison →

Drop-in SDKs

Open-source Python, Node.js, and PHP SDKs. Install, pass your API key, call validate(). Replace XML endpoints with REST in one afternoon.

PyPI npm Packagist

Your keys, our infrastructure

Bring your own USPS Developer Portal credentials. We handle OAuth token lifecycle, rate limits, and encrypted storage. Your data stays yours, AES-GCM encrypted at rest.

Migrate in three steps

Replace your USPS Web Tools XML integration with a modern REST API. Most developers ship within an hour.

Get your API key

Install the SDK

pip install usps-v3 or npm install usps-v3. Replace secure.shippingapis.com XML calls with typed REST methods.

Ship

Validate addresses, compare rates, and create labels. Add tracking, batch validation, and BYOK when you need them.

Get started in minutes

Pick your language. Install the SDK. Validate an address.

PyPI npm Packagist GitHub

# Validate an address (free tier)
curl "https://api.revaddress.com/api/address/validate\
?streetAddress=1600+Pennsylvania+Ave&city=Washington&state=DC&ZIPCode=20500" \

# 200 OK — 42ms
{
  "streetAddress": "1600 PENNSYLVANIA AVE NW",
  "ZIPCode": "20500",
  "DPVConfirmation": "Y"
}

# Install
pip install usps-v3

# Validate an address
from usps_v3 import Client

client = Client("your_api_key")
result = client.addresses.validate(
    street="1600 Pennsylvania Ave",
    city="Washington",
    state="DC",
    zip_code="20500"
)

print(result.zip)  # "20500-0005"
print(result.dpv)  # "Y" (deliverable)

// Install: npm install usps-v3
import { USPSClient } from 'usps-v3';

const client = new USPSClient("your_api_key");
const result = await client.addresses.validate({
  street: "1600 Pennsylvania Ave",
  city: "Washington",
  state: "DC",
  zipCode: "20500"
});

console.log(result.zip);  // "20500-0005"
console.log(result.dpv);  // "Y" (deliverable)

// Install: composer require revaddress/usps-v3-php
use RevAddress\USPSv3\Client;

$usps = new Client('your-client-id', 'your-client-secret');
$result = $usps->validateAddress([
    'streetAddress' => '1600 Pennsylvania Ave NW',
    'city'          => 'Washington',
    'state'         => 'DC',
    'ZIPCode'       => '20500',
]);

echo $result['address']['ZIPCode'];  // "20500-0005"
echo $result['address']['DPVConfirmation'];  // "Y"

Start shipping in 5 minutes

Free tier for validation and rates. Flat monthly pricing when you need more.

Get Free API Key Read the Docs

The USPS API you wish existed.