Cloud-based personal health records increase globally. The GPOC series introduces the concept of a Global Patient co-Owned Cloud (GPOC) of personal health records. Here, we present the GPOC series’ technical sandbox. This to facilitate online research and testing of the concept and its security, encryption, movability, research potential, risks and structure. It has several protocols for homomorphic encryption, decentralisation, transfers and file management. The Sandbox is openly available online and tests authorisation, transmission, access control and integrity live. It invites all committed parties to test and improve the platform. Both individual patients, clinics, organisations and regulators are invited to test the concept. The GPOC Sandbox displays a co-ownership of personal health records. Here it is trisected between patients, clinics and clinicians. The patient can actively participate in research and control their health data. GPOC may influence global research and dissemination of artificial intelligence in healthcare. This may impact global health.