invowerk API alternatives

Validate e-invoices (ZUGFeRD, Factur-X, XRechnung, Peppol BIS) and get a validation report. If it doesn't fit your project, here are the 10 best free Data Validation APIs to use instead in 2026, out of 15 in the directory.

For reference, invowerk API: HTTPS.

1
US Autocomplete API
Online · 976 ms
Enter address data quickly with real-time address suggestions.
- Callable from the browser (CORS)
- HTTPS
apiKeyHTTPSCORS
2
US Street Address API
Online · 559 ms
Validate and append data for any US postal address.
- Callable from the browser (CORS)
- HTTPS
apiKeyHTTPSCORS
3A
Attestwire API
Online · 700 ms
Validate EN 16931 e-invoices: XRechnung, ZUGFeRD, Factur-X, Peppol BIS.
- Callable from the browser (CORS)
- HTTPS
apiKeyHTTPSCORS
4T
Temsor API
Online · 668 ms
Validates Turkish national ID, tax number, IBAN, phone, plate and parses addresses.
- Callable from the browser (CORS)
- HTTPS
apiKeyHTTPSCORS
5
US Extract API
Online · 520 ms
Extract postal addresses from any text including emails.
- Callable from the browser (CORS)
- HTTPS
apiKeyHTTPSCORS
6
Postman Echo API
Online · 2932 ms
Test api server to receive and return value from HTTP method.
- No API key needed
- HTTPS
No authHTTPSCORS ?
7
VATlayer API
Online · 887 ms
Free and HTTPS secured JSON API offering instant VAT number validation, reliable EU VAT rates and VAT compliant price calculations for developers & businesses.
- HTTPS
apiKeyHTTPSCORS ?
8
SchemaShield API
Online · 499 ms
Read-only preflight for breaking schema changes and downstream query impact.
- HTTPS
apiKeyHTTPSCORS ?
9
Lob.com API
Online · 2690 ms
Automate and personalize direct mail at scale while our nationwide print network speeds delivery, controls postage costs, and keeps every send compliant.
- HTTPS
apiKeyHTTPSCORS ?
10
RevAddress API
Online · 966 ms
US address standardization, congressional and state legislative districts, Census data; free tier.
- HTTPS
apiKeyHTTPSNo CORS

invowerk API vs alternatives

invowerk API compared with its alternatives
API	API key	HTTPS	CORS	Uptime	Response	Rating
invowerk	Required	Yes	Unknown	Up	727 ms	Not rated
US Autocomplete	Required	Yes	Yes	Up	976 ms	Not rated
US Street Address	Required	Yes	Yes	Up	559 ms	Not rated
Attestwire	Required	Yes	Yes	Up	700 ms	Not rated
Temsor	Required	Yes	Yes	Up	668 ms	Not rated
US Extract	Required	Yes	Yes	Up	520 ms	Not rated
Postman Echo	No	Yes	Unknown	Up	2932 ms	Not rated
VATlayer	Required	Yes	Unknown	Up	887 ms	Not rated
SchemaShield	Required	Yes	Unknown	Up	499 ms	Not rated

invowerk API alternatives FAQ

What is the best free alternative to the invowerk API in 2026?

The top-ranked free alternatives to the invowerk API are US Autocomplete API, US Street Address API and Attestwire API, all in the Data Validation category. Rankings combine access (API key, HTTPS, CORS), daily uptime checks and developer ratings.

Is there a invowerk API alternative that doesn't need an API key?

Yes: Postman Echo API and PurgoMalum API work without an API key, unlike the invowerk API, which uses apiKey authentication.

Is there a invowerk API alternative I can call from the browser?

US Autocomplete API, US Street Address API and Attestwire API support CORS, so front-end JavaScript can call them directly.

How many Data Validation APIs are similar to the invowerk API?

The directory lists 15 other free Data Validation APIs. This page compares the top ones side by side.