Overview
Lob.com provides a US Address Verification API that validates, standardizes, and geocodes US mailing addresses using USPS data, ensuring mail deliverability and cleaning up address databases. It also supports international address verification, address autocomplete, and physical mail sending (postcards, letters, checks) via API. The free test mode allows unlimited verifications against a sandbox environment.
Beginner Tip
Create an account at lob.com and use the test API key (prefixed with `test_`) for free sandbox verification. The verification endpoint is `https://api.lob.com/v1/us_verifications`. Authentication uses HTTP Basic Auth — set the API key as the username with an empty password. Test keys return standardized results but do not charge credits.
Available Data
Example Response
{
"status": "success",
"data": {
"result": "Data from Lob.com",
"description": "US Address Verification",
"timestamp": "2025-01-15T10:00:00Z"
}
} Field Reference
deliverability USPS deliverability status: `deliverable`, `deliverable_unnecessary_unit`, `deliverable_incorrect_unit`, `deliverable_missing_unit`, or `undeliverable`. primary_line The standardized first line of the address (street number and name). last_line The standardized city, state, and ZIP+4 code on the last line. components Parsed address components including street number, street name, city, state, zip code, and zip+4. urbanization Urbanization code used for Puerto Rico addresses; empty for continental US addresses. Implementation Example
const url = "https://lob.com/";
// Replace headers or query params with the values required by this API.
const response = await fetch(url, {
headers: {
"X-API-Key": "YOUR_API_KEY"
}
});
if (!response.ok) throw new Error(`Request failed: ${response.status}`);
const data = await response.json();
console.log(data); What Can You Build?
Note: These code examples are AI-generated and unverified. Always refer to the official API documentation for accurate usage.
Common Errors & Troubleshooting
Metadata Score Breakdown
Estimated from metadata — endpoint not independently tested
Metadata estimate · endpoint not independently tested
Technical Specifications
Related Tags
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