Data Validation APIs let you add data validation capabilities without building from scratch. Every entry below is profiled with trust signals — pricing model, authentication requirements, CORS support, rate limits, and live uptime checks — so you can compare options and pick production-safe choices instead of guessing from a link list.
| API | Pricing | Auth | CORS | Health | |
|---|---|---|---|---|---|
| API Adresse Official French address validation service | Free | No | No | Profile | |
| Attestwire API Validate EN 16931 e-invoices: XRechnung, ZUGFeRD, Factur-X, Peppol BIS | Free | API Key | Yes | Profile | |
| BigDataCloud's Phone and Email Verification API Syntax and Format Validation of Phone Number and Email address. | Freemium | API Key | No | Profile | |
| Brevo Suit Connection for brevo CRM suite | Freemium | API Key | Unknown | Profile | |
| Lob.com US Address Verification | Paid | API Key | No | Profile | |
| Nonprofit Check Plus Verify charities via EIN using IRS, PUB78, BMF & OFAC data for compliance and legitimacy | Free | API Key | No | Profile | |
| Postman Echo Test api server to receive and return value from HTTP method | Free | No | No | Profile | |
| PurgoMalum Content validator against profanity & obscenity | Free | No | No | Profile | |
| SchemaShield API Read-only preflight for breaking schema changes and downstream query impact | Paid | API Key | Unknown | Profile | |
| Temsor API Validates Turkish national ID, tax number, IBAN, phone, plate and parses addresses | Paid | API Key | Yes | Profile | |
| Timezones Dictionary API This API returns a list of all available timezones for your application | Free | API Key | No | Profile | |
| US Autocomplete Enter address data quickly with real-time address suggestions | Paid | API Key | Yes | Profile | |
| US Extract Extract postal addresses from any text including emails | Paid | API Key | Yes | Profile | |
| US Street Address Validate and append data for any US postal address | Paid | API Key | Yes | Profile | |
| VATlayer API VAT number validation | Paid | API Key | Unknown | Profile | |
| Validate UK Postcodes This API validates postal codes within UK | Freemium | API Key | No | Profile | |
| VatcheckAPI VAT Number Validation & Lookup REST API | Paid | API Key | No | Profile |
Start with pricing and auth: free tiers and no-auth APIs are fastest to prototype with. Then check CORS if your app calls the API from the browser, and health before you commit — a great API that's been down for a week will block your launch. Each profile below shows all of these signals plus rate limits where documented.