

US Address Verification.
Lob.com API is a free Data Validation API that requires apiKey authentication, is served over HTTPS and has unconfirmed CORS support.
Automate and personalize direct mail at scale while our nationwide print network speeds delivery, controls postage costs, and keeps every send compliant.
Details from lob.com.

Unified API suite · now live
Geocode an address, validate an email, track a flight or pull stock data with one account, one dashboard and one API key.
Validate EN 16931 e-invoices: XRechnung, ZUGFeRD, Factur-X, Peppol BIS
US address standardization, congressional and state legislative districts, Census data; free tier
The Lob.com API is provided by Lob (lob.com). Automate and personalize direct mail at scale while our nationwide print network speeds delivery, controls postage costs, and keeps every send compliant.
Yes. The Lob.com API is listed in the Data Validation category of the public-apis directory, which only includes APIs that are free or have a free tier. Check its documentation for rate limits and paid plans.
Yes. The Lob.com API uses apiKey authentication, so you need to register for credentials before making requests.
CORS support for the Lob.com API is unknown. Test a request from the browser, and fall back to a server-side call if it is blocked.
Yes. The Lob.com API is served over HTTPS, so it's safe to use in production.