Address Validation APIs
Address validation APIs check that an address is real and return it in a standard format. Smarty's US Street Address API validates against USPS and proprietary data, and its Autocomplete Pro suggests verified addresses as users type, both on free trials. Lob.com standardizes US mailing addresses on paid plans, while TrustyData handles French address verification and geocoding from open data.
| API | Pricing | Auth | Format | Free tier | Status |
|---|---|---|---|---|---|
Lob.comVerifies, autocompletes and standardizes US mailing addresses, plus ZIP and reverse-geocode lookups. Location & Mapping › Address & Postal Code | Paid | API key | JSON | — | Live |
RevAddressUS address standardization, parsing, and geocoding on Census data, with BYOK USPS verification. Location & Mapping › Address & Postal Code | Freemium | API key | JSON | <100/day | Down |
Smarty US Autocomplete ProAutocompletes and validates US street addresses against USPS data as users type. Location & Mapping › Address & Postal Code | Free trial | API key | JSON | <100/day | Live |
TrustyDataFrench address verification, geocoding, SIRENE company search and trade-area analysis from open data. Location & Mapping › Address & Postal Code | Freemium | API key | JSON | 1k–10k/day | Live |
US Street AddressValidates and standardizes US street addresses against USPS and proprietary datasets. Location & Mapping › Address & Postal Code | Free trial | API key | JSON | — | Live |
Lob.comPaidLive
Verifies, autocompletes and standardizes US mailing addresses, plus ZIP and reverse-geocode lookups.
API key · JSON
—
no machine-readable spec
RevAddressFreemiumDown
US address standardization, parsing, and geocoding on Census data, with BYOK USPS verification.
API key · JSON
<100/day
OpenAPI spec · llms.txt
Smarty US Autocomplete ProFree trialLive
Autocompletes and validates US street addresses against USPS data as users type.
API key · JSON
<100/day
no machine-readable spec
TrustyDataFreemiumLive
French address verification, geocoding, SIRENE company search and trade-area analysis from open data.
API key · JSON
1k–10k/day
llms.txt
US Street AddressFree trialLive
Validates and standardizes US street addresses against USPS and proprietary datasets.
API key · JSON
—
no machine-readable spec
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Choosing an Address Validation API
Is there a free Address Validation API?
Yes. TrustyData has a free tier alongside paid plans.
Which Address Validation APIs work without an API key?
All of them need a key or account. TrustyData gives one out free when you sign up.
Can I use Address Validation APIs in a commercial project?
US Street Address and Smarty US Autocomplete Pro permit commercial use.
Broader: Address & Postal Code APIs · Location & Mapping APIs
More in Address & Postal Code: ZIP Code Lookup APIs