We develop a web interface that generates multi-track music loop sequences. Our system takes musical metadata from users as input conditions and generates MIDI token events that can be played seamlessly. The core component, the loop generation model, is trained with loop sets that have been extracted by observing the repetitive structure of music. Also, the metadata tokens are randomly dropped to ensure flexible controllability during training. Our interface is available at https://github.com/sjhan91/loop-demo.