Growing demand to reduce fuel consumption has accelerated the application of Al sheets to the body structure of automobiles. While recent studies on laser welding of Al 5xxx series and Al 6xxx series alloys have examined weldability, the laser autogenous welding usually results in low gap bridging capability and weld defects such as porosity, underfill, cracking, and so on. In this study, we evaluated the gap bridging capability and the crack sensitivity during laser autogenous welding, laser welding with filler wire, and laser-arc hybrid welding, respectively. Al 5J32 and 6K21 sheets were used as the base metal and Al 4xxx series and Al 5xxx series wires were used as the filler metal. Employing adequate welding conditions, the gap bridging capability during butt welding was investigated for each welding process. To clarify the solidification crack sensitivity, bead-on-plate welding was implemented for a tapered specimen as a self-restraint crack test. Compared with the laser autogenous welding, laser welding with filler wire and the laser-arc hybrid welding showed improved gap bridging capability and reduced crack sensitivity.