Initially, bulk metallic glasses (BMGs) were developed and produced using rapid solidification techniques such as splat quenching, melt spinning and suction casting. While some BMG grades can be thermoformed within their supercooled liquid temperature range, parts produced by these traditional methods tend to be simple in shape and relatively small (few millimeters in width). This ensures that the cooling rates are high enough to bypass the crystallization throughout the part and thereby freeze the atomic disorder of the liquid. Recently, laser-based additive manufacturing (AM) has been explored as a potential route to bypass these limitations. This technique offers the possibility of achieving high cooling rates upon solidification thanks to the fast-travelling localized melt pool. However, there are challenges to fully benefit from the AM design freedom, associated with the inherent reheating of the already deposited layers upon manufacturing. To avoid local structural changes associated with reheating in the heat affected zone, low laser energy is typically used by working with low laser power (≤100 W) and small layer thicknesses (~20 µm). The present work sheds light on the consolidation mechanisms at play within that low energy processing regime for a Zr-based BMG thanks to in situ Xray microtomography and a dedicated LPBF rig for synchrotron measurement. Optimization of the laser scanning strategy will be presented and the relationship between porosity and the material behavior under compression loading will be discussed. The results connect process – property – performance of LPBF Zr-based BMGs and demonstrate why pores should be considered more than mere defects in BMGs.