Data Validation — entry 002 of 7
Lob.com
Lob's US Address Verification API checks, standardizes, and CASS-certifies a US postal address in real time, returning delivery-point-validation flags, vacancy and building-type metadata, and a corrected/deliverable address in one JSON response. It's the same verification engine behind Lob's broader direct-mail automation platform (mail creation, printing, and USPS tracking), so a key created for one Lob product works across the rest. Authentication is a single API key sent as the HTTP Basic Auth username, with separate test and live keys so integrations can be built and tested before any usage is billed.
AuthenticationAPI KeySign up with the provider to obtain credentials.
HTTPSSupportedTraffic is encrypted in transit.
CORSEnabledCallable directly from browser JavaScript.
PricingMeteredBilled per request beyond a limited free quota.
FormatsJSONResponses can be requested as JSON.
GreatAPIs Score
Score69
Authentication15/25API key required
Pricing11/20Metered / usage-based pricing
Docs14/20Documentation URL provided
Formats9/15Single response format
Freshness20/20Verified within 6 months
Embed this badge
<a href="https://greatapis.com/api/lob-com/"><img src="https://greatapis.com/badge/lob-com.svg" alt="Scored 69 on greatapis.com"></a>Auth quickstart
- Sign up with the provider to get an API key.
- Send it on every request as a header
Authorization: <key> - The exact header isn't documented — Authorization is a common default; confirm in the provider's docs.
Stored keyNo key stored
Your key is stored only in this browser (localStorage) and sent directly to the API — never to greatapis.