
Postal code search, country exports, and address validation data.
PostalCodes API is a free Geocoding API that requires no API key, is served over HTTPS and has unconfirmed CORS support.
Postal code API integration patterns for JSON lookup, postal code search, country exports, autocomplete and address validation workflows on postalcodes.info.
Details from postalcodes.info.

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The PostalCodes API is provided by Postalcodes.info (postalcodes.info). Postal code API integration patterns for JSON lookup, postal code search, country exports, autocomplete and address validation workflows on postalcodes.info.
Yes. The PostalCodes API is listed in the Geocoding category of the public-apis directory, which only includes APIs that are free or have a free tier. Check its documentation for rate limits and paid plans.
No. The PostalCodes API requires no authentication, so you can start making requests without signing up.
CORS support for the PostalCodes API is unknown. Test a request from the browser, and fall back to a server-side call if it is blocked.
Yes. The PostalCodes API is served over HTTPS, so it's safe to use in production.