Data Validation — entry 005 of 7
US Autocomplete
Smarty's US Autocomplete Pro API suggests valid, USPS-backed US addresses as a user types, turning a single free-form "search" string into a ranked list of deliverable candidates for checkout and signup forms, with optional city/state/ZIP filters to narrow the results. A separate "selected" parameter expands a chosen address into its individual secondary units (apartments, suites) when it resolves to more than one. It's part of Smarty's wider address-data platform, so one account and key also unlock the sibling US Street Address and US Extract APIs.
AuthenticationAPI KeySign up with the provider to obtain credentials.
HTTPSSupportedTraffic is encrypted in transit.
CORSEnabledCallable directly from browser JavaScript.
PricingFreemiumA usable free tier exists, with paid plans for more volume.
FormatsJSONResponses can be requested as JSON.
GreatAPIs Score
Score61
Authentication15/25API key required
Pricing17/20Freemium tier available
Docs0/20No docs or spec available
Formats9/15Single response format
Freshness20/20Verified within 6 months
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<a href="https://greatapis.com/api/us-autocomplete/"><img src="https://greatapis.com/badge/us-autocomplete.svg" alt="Scored 61 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.