The control of the high intensity beams of the CERN Large Hadron Collider is particular challenging and requires a good modeling of the machine. In recent years efforts were devoted to the design of a software infrastructure aimed at mimicking the behavior of the LHC. An online model of the machine, based on the accelerator design tool MAD-X, has been developed to support the commissioning and the operation of the LHC. This model is integrated into the Java-based LHC development framework and provides the full computing power of MAD-X, including the best knowledge of the machine aperture and magnetic models. In this paper, we present the status of the MAD-X online application and illustrate how it has been used during the LHC commissioning. Possible future implementations are also discussed.