data-validation APIs

VATlayer is a REST API for validating EU VAT numbers in real time against official EU VIES (VAT Information Exchange System) data, returning company name, address, and registration status.

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.

Postman Echo is a free HTTP test server that mirrors back exactly what you send — headers, query parameters, body, cookies, and request method — making it invaluable for debugging API clients and understanding HTTP behavior without needing a real backend.

PurgoMalum is a free, no-auth REST API for filtering profanity and obscene words from text, returning a cleaned version with offensive terms replaced by asterisks or a custom fill character.

Smarty's US Autocomplete Pro API provides real-time US address suggestions as users type, returning up to 10 valid USPS-deliverable address candidates per query to reduce data entry errors and speed up checkout flows.

Smarty's US Extract API scans any block of unstructured text — emails, documents, web pages — and extracts all US postal addresses it finds, then validates each one against USPS data for deliverability.

The Smarty US Street Address API validates and enriches US postal addresses in real time, returning standardized components like delivery line, city, state, ZIP+4, and county FIPS code.