IP geolocation with proxy, VPN and datacenter risk and the age of the evidence.
IP99 API is a free Geocoding API that requires no API key, is served over HTTPS and supports CORS, so it can be called from the browser.
Free IP risk and geolocation API. Proxy, VPN, dial-up pool, cloud phone and datacenter detection with ASN and city-level geo. No signup required.
Details from ip99.com.

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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.
Unlimited free IP Address API with useful information
The IP99 API is provided by IP99 API (ip99.com). Free IP risk and geolocation API. Proxy, VPN, dial-up pool, cloud phone and datacenter detection with ASN and city-level geo. No signup required.
Yes. The IP99 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 IP99 API requires no authentication, so you can start making requests without signing up.
Yes. The IP99 API supports CORS, so front-end JavaScript can call it directly.
Yes. The IP99 API is served over HTTPS, so it's safe to use in production.