We report testing strategies and apparatus for the testing of flexible electronic devices and systems. To make reliable electrical connections for flexible electronic devices under mechanical flexibility testing, we use an anisotropic conductive film bonding of flexible extension cables to long connection leads on the flexible sample. This allows electrical connections without mechanically interfering with the devices under test. We report three platforms for flexible device testing: a simple push-to-flex apparatus that provides unguided bending of a flexible sample, a roller-flex apparatus that uses a roller to provide controlled-radius bending, but applies some tensile force to the sample, and an on-belt-flex apparatus that uses a secondary flexible substrate to provide controlled-radius bending without additional tensile stress. These flexible testing approaches are useful tools to obtain electrical properties for flexible electronic devices and systems as a function of bending or flexing.