NumValidate
Data Validation
Open Source phone number validation
No keyHTTPS
Free Data Validation APIs
Free public APIs for data validation, each one verified and kept up to date.
19 listed · 3 need no key · 10 work in the browser
Postman Echo
Data Validation
Test api server to receive and return value from HTTP method
No keyHTTPS
PurgoMalum
Data Validation
PurgoMalum is a free RESTful web service that filters and removes profanity and unwanted text from input. It supports customization options and can return the results in plain text, XML, or JSON formats.
No keyHTTPS
DataScreenIQ
Data Validation
Screen data for schema drift, type mismatches, and null rate anomalies
API keyCORSHTTPS
SpryTools Email Validation
Data Validation
Syntax + MX + disposable/role-based email validation
API keyCORSHTTPS
Temsor
Data Validation
Validates Turkish national ID, tax number, IBAN, phone, plate and parses addresses
API keyCORSHTTPS
US Autocomplete
Data Validation
Enter address data quickly with real-time address suggestions
API keyCORSHTTPS
US Autocomplete
Data Validation
Enter address data quickly with real-time address suggestions
API keyCORSHTTPS
US Extract
Data Validation
Extract postal addresses from any text including emails
API keyCORSHTTPS
US Extract
Data Validation
Extract postal addresses from any text including emails
API keyCORSHTTPS
US Street Address
Data Validation
Validate and append data for any US postal address
API keyCORSHTTPS
US Street Address
Data Validation
Validate and append data for any US postal address
API keyCORSHTTPS
VerifyEd
Data Validation
Verify academic credentials — 912K+ schools, 2,592 diploma mills
API keyCORSHTTPS
Attestwire
Data Validation
Validate EN 16931 e-invoices: XRechnung, ZUGFeRD, Factur-X, Peppol BIS
API keyHTTPS
Kiprio Email Validation
Data Validation
This API validates email addresses through syntax checks, MX record lookup, detection of disposable emails, and identification of role-based addresses, along with typo suggestions. It provides a confidence score for the validity of the email address in real-time. The service supports 100 free requests per day and offers a pro tier for larger usage.
API keyHTTPS
Lob.com
Data Validation
US Address Verification
API keyHTTPS
SchemaShield
Data Validation
Read-only preflight for breaking schema changes and downstream query impact
API keyHTTPS
Trestle
Data Validation
Validates the phone number and provides phone metadata
API keyHTTPS
VATlayer
Data Validation
VAT number validation
API keyHTTPS
All 19 Data Validation APIs
Free Data Validation APIs — common questions
Counts and timings below come from our own scheduled checks of this category.
How many free data validation APIs are there?
We track 19 in this category, of which 19 responded at our last check. 3 of them need no API key.
Which data validation APIs work without an API key?
3 of the 19 entries here need no credential. Filter this page by "no key" to see them, or browse the no-key collection for every keyless API across all categories.
Can I use these data validation APIs in a browser app?
None of the entries in this category currently combine no-key access with CORS headers, so you will need a small server-side proxy to use them from browser JavaScript.
Which is the fastest free data validation API?
Of the keyless options that responded at our last check, NumValidate was quickest at a median 460 ms. Speed is only one factor — coverage and licensing usually matter more — but it is measured here rather than claimed.
How do you know these APIs still work?
We call every listing on a schedule and record the status code, response time and whether CORS headers came back. Those results drive the badges on this page. Across the whole catalogue, 487 of 2,712 entries were not responding at the last full run, which is the sort of thing an unchecked list never tells you.