IBGE
Aggregate services of IBGE (Brazilian Institute of Geography and Statistics)
Map an IP to a country.
IP 2 Country API is a free Geocoding API that requires no API key, is served over HTTPS and has unconfirmed CORS support.
JSON API returns the country of an IP address. Simple, fast, free. For open source projects only.
Details from ip2country.info.

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Geocode an address, validate an email, track a flight or pull stock data with one account, one dashboard and one API key.
Aggregate services of IBGE (Brazilian Institute of Geography and Statistics)
API for accessing geo-data of Hong Kong
Ip to location with country code, currency code & currency name, fast response, unlimited requests
The IP 2 Country API is provided by IP 2 Country / IP Geolocation JSON API (ip2country.info). JSON API returns the country of an IP address. Simple, fast, free. For open source projects only.
Yes. The IP 2 Country 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 IP 2 Country API requires no authentication, so you can start making requests without signing up.
CORS support for the IP 2 Country API is unknown. Test a request from the browser, and fall back to a server-side call if it is blocked.
Yes. The IP 2 Country API is served over HTTPS, so it's safe to use in production.