IPInfo.io is a highly reliable, lightning fast, and mature geolocation API. It allows you to not only pinpoint the user location, but also find information regarding the ISP, IP type, and carrier. It comes with an extensive, developer friendly documentation to help you quickly get started. On the top, it provides both free and paid plans. With the free plan, you can make 1000 requests per day and check out if you really need it.
Having a threat-intelligence based security solution can help your organization to effectively battle against these dynamically changing threats. And while looking for such competent solution, I just happened to come across the Threat Intelligence Platform by WhoisXml API. Threat Intelligence Platform provides you an easy to use threat intelligence tools and APIs. It helps you to get comprehensive details about targeted hosts and the complete infrastructure behind them.