What are data validation APIs?

Data validation APIs verify the accuracy and format of user-submitted data including email addresses, phone numbers, postal addresses, credit card numbers, and VAT IDs to reduce form errors and fraud.

How do I validate an email address with an API?

Send a GET or POST request with the email address to an email validation API. The response typically includes syntax checks, domain verification, and mailbox existence checks (SMTP verification).

Are data validation APIs GDPR compliant?

Most reputable data validation API providers publish GDPR compliance documentation. Review each provider's data processing agreement before sending personal data to ensure compliance.

Data Validation APIs

Data validation and verification

7 APIs in this category

Showing 7 of 7 APIs

Lob.com

Verify and standardize U.S. postal addresses in real time

Auth: apiKey HTTPS CORS: Unknown

Postman Echo

Simple API testing service to echo back HTTP requests for debugging

Auth: No HTTPS CORS: Unknown

PurgoMalum

Filter and validate content against profanity and obscenity

Auth: No HTTPS CORS: Unknown

US Autocomplete

Provide real-time address suggestions for faster data entry

Auth: apiKey HTTPS CORS: Yes

US Extract

Extract postal addresses from raw text or emails automatically

Auth: apiKey HTTPS CORS: Yes

US Street Address

Validate, correct, and append metadata for any U.S. address

Auth: apiKey HTTPS CORS: Yes

vatlayer

Validate VAT numbers and retrieve company information across the EU

Auth: apiKey HTTPS CORS: Unknown

API	Description	Auth	HTTPS	CORS
Lob.com	Verify and standardize U.S. postal addresses in real time	apiKey	✓	?
Postman Echo	Simple API testing service to echo back HTTP requests for debugging	No	✓	?
PurgoMalum	Filter and validate content against profanity and obscenity	No	✗	?
US Autocomplete	Provide real-time address suggestions for faster data entry	apiKey	✓	✓
US Extract	Extract postal addresses from raw text or emails automatically	apiKey	✓	✓
US Street Address	Validate, correct, and append metadata for any U.S. address	apiKey	✓	✓
vatlayer	Validate VAT numbers and retrieve company information across the EU	apiKey	✓	?

Best Data Validation APIs for Developers

A data validation API allows developers to verify the accuracy and integrity of user-submitted data in real time: email addresses, phone numbers, postal addresses, and more. These APIs reduce form errors, improve data quality, and help prevent fraudulent submissions.

CodeHelper's curated data validation API collection includes APIs covering email verification, phone validation, address standardization, and general input sanitation.

What to look for in a data validation API

Validation depth: Basic syntax checks differ from deep SMTP verification; choose the level of rigor your use case requires.
Response speed: For real-time form validation, prioritize APIs with sub-200ms response times to avoid UI lag.
Bulk validation support: For cleaning existing datasets, choose APIs that support batch processing endpoints.

How to use this API directory

Browse the curated list of APIs below.
Click any API to visit its documentation.
Check the Auth column to understand what credentials you need.

Whether you are validating sign-up forms or cleaning a CRM database, this free curated API directory saves you hours of research.

Data Validation APIs

Lob.com

Postman Echo

PurgoMalum

US Autocomplete

US Extract

US Street Address

vatlayer

Best Data Validation APIs for Developers

What to look for in a data validation API

How to use this API directory

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