Among the development of technology, a large number of medical devices have been designed, improved, and implemented in various forms and functions to facilitate therapy and treatment (e.g., medical guidewires, catheters, implants). Remote controllability, real-time response, size, and non-toxicity of the devices are all critically required to operate in the blind, unstructured, and fluidic environments of biomedical regions. Herein, an untethered soft swimming milli-robot has been developed to fulfill the remote operation in such regions. The robot employs magnetic property as a motor-less mechanism powered by the dynamic magnetic field. Non-uniform magnetization embedded in the soft structure allows the robot to propagate the body-wave deformation utilizing a high degree of freedom provided by magnetic compliance for swimming in the fluid. The robot is experimentally investigated in the swimming performance under the different control parameters. The results report that the swimming velocity is directly proportional to the strength and frequency of the actuating magnetic field. It swims with the fastest velocity about 5.5 mm/s, under 15 mT and 13 Hz of the oscillating magnetic field. On the other hand, swimming velocity is dramatically dropped since the frequency is over 13 Hz. The magnetically controllable robot is capable of applying for various purposes, especially where the demand concerns small size, soft interface, and remote controllability.