In recent years, increasing cost pressure and increasing technical demands on mechanical properties lead in series production to a substitution of already established welding processes. Besides economic advantages, new process technologies are implemented due to better technological reasons by steady improvements and new features. Diode lasers are part of those and are in use by a different wavelength range from blue to infrared adapted for explicit base material choices like copper for blue or e.g. low carbon steels for infrared. Besides the wavelength, the thickness of different materials has an influence on the heat distribution, while different mechanical properties are required from thin to thick. However, all welding applications require a special temperature profile to meet on the one hand side a sufficient seam formation and on the other hand the mechanical properties. By their beam formation, diode lasers fulfill a couple of demands directly. For thinner base material applications, there is the possibility by a special multispot technology to do a beam shaping with improvements on the process behavior and the seam formation. Besides those advantages, an additional benefit on the mechanical properties is given. In this contribution, we review the application range and advantages by diode laser technology on the seam formation by using different beam formations with correlating them to the influence on the mechanical properties.