Live migration, the process of transferring a running application to a different physical location with minimal downtime, can provide many benefits desired by modern cloudbased systems. Furthermore, live migration between different cloud providers enables a new level of freedom for cloud users to move their workloads around for performance or business objectives without having to be tied down to any single provider. While this vision is not new, to-date, there are few solutions and proof-of-concepts that provide this capability. As containerized applications are gaining popularity, we focus on the design and implementation of live migration of containers across cloud providers. CloudHopper, our proof-of-concept live migration service for containers to hop around between Amazon Web Services, Google Cloud Platform, and Microsoft Azure is evaluated using a common web-based workload. CloudHopper is automated and supports pre-copy optimization, connection holding, traffic redirection, and multiple interdependent container migration. It is applicable to a broad range of application use cases.